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Integrating Building Information Modeling and Green Building Certification

Permanent Link: http://ufdc.ufl.edu/UFE0041603/00001

Material Information

Title: Integrating Building Information Modeling and Green Building Certification the BIM-LEED Application Model Development
Physical Description: 1 online resource (181 p.)
Language: english
Creator: Wu, Wei
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2010

Subjects

Subjects / Keywords: aec, application, bim, building, certification, framework, green, integration, leed, model, rating, sustainability, system
Design, Construction, and Planning -- Dissertations, Academic -- UF
Genre: Design, Construction, and Planning Doctorate thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: Building information modeling (BIM) and green building are currently two major trends in the architecture, engineering and construction (AEC) industry. This research recognizes the market demand for better solutions to achieve green building certification such as LEED in the United States. It proposes a new strategy based on the integration of BIM and green building rating systems. The research firstly conducted a feasibility survey to investigate two fundamental questions in the BIM and LEED integration: 1) what LEED certification requires; and 2) what functionality BIM possess to assist compliance with such requirements. Based on the match-up of LEED certification requirements with the functionality inventory of popular BIM software solutions, a framework was then established to prepare the theoretical foundation for pragmatic solutions to support this integration. The BIM-LEED application model was created to handle practical problems at the credit level that might occur in actual LEED projects. It consisted of two modules: Design Assistance and Certification Management. The Design Assistance module took advantage of the Autodesk Revit API to provide the designers with off-the-shelf LEED knowledge built into the BIM software to ensure the design was LEED-oriented. The Certification Management module was a web application built upon the Apache/MySQL/PHP platform that focused on managing project information, LEED documentation and submittals for the certification purpose. Finally, the LEED Materials and Resources use case was created to preliminarily validate the application model by simulating the LEED project delivery process. Overall, this research proposed and demonstrated that the BIM-LEED integration was feasible with considerable constraints. The integration should accommodate the needs of different team members with specialized assistance at different stage of the project delivery process. New functionalities of BIM software solutions and better support for information exchange at the database level would facilitate more rigorous implementation of BIM in green building certification.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Wei Wu.
Thesis: Thesis (Ph.D.)--University of Florida, 2010.
Local: Adviser: Issa, R. Raymond.
Local: Co-adviser: Kibert, Charles J.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2012-08-31

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2010
System ID: UFE0041603:00001

Permanent Link: http://ufdc.ufl.edu/UFE0041603/00001

Material Information

Title: Integrating Building Information Modeling and Green Building Certification the BIM-LEED Application Model Development
Physical Description: 1 online resource (181 p.)
Language: english
Creator: Wu, Wei
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2010

Subjects

Subjects / Keywords: aec, application, bim, building, certification, framework, green, integration, leed, model, rating, sustainability, system
Design, Construction, and Planning -- Dissertations, Academic -- UF
Genre: Design, Construction, and Planning Doctorate thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: Building information modeling (BIM) and green building are currently two major trends in the architecture, engineering and construction (AEC) industry. This research recognizes the market demand for better solutions to achieve green building certification such as LEED in the United States. It proposes a new strategy based on the integration of BIM and green building rating systems. The research firstly conducted a feasibility survey to investigate two fundamental questions in the BIM and LEED integration: 1) what LEED certification requires; and 2) what functionality BIM possess to assist compliance with such requirements. Based on the match-up of LEED certification requirements with the functionality inventory of popular BIM software solutions, a framework was then established to prepare the theoretical foundation for pragmatic solutions to support this integration. The BIM-LEED application model was created to handle practical problems at the credit level that might occur in actual LEED projects. It consisted of two modules: Design Assistance and Certification Management. The Design Assistance module took advantage of the Autodesk Revit API to provide the designers with off-the-shelf LEED knowledge built into the BIM software to ensure the design was LEED-oriented. The Certification Management module was a web application built upon the Apache/MySQL/PHP platform that focused on managing project information, LEED documentation and submittals for the certification purpose. Finally, the LEED Materials and Resources use case was created to preliminarily validate the application model by simulating the LEED project delivery process. Overall, this research proposed and demonstrated that the BIM-LEED integration was feasible with considerable constraints. The integration should accommodate the needs of different team members with specialized assistance at different stage of the project delivery process. New functionalities of BIM software solutions and better support for information exchange at the database level would facilitate more rigorous implementation of BIM in green building certification.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Wei Wu.
Thesis: Thesis (Ph.D.)--University of Florida, 2010.
Local: Adviser: Issa, R. Raymond.
Local: Co-adviser: Kibert, Charles J.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2012-08-31

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2010
System ID: UFE0041603:00001


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1 INTEGRAT ING BUILDING INFORMATION MODELING AND GREEN BUILDING CERTIFICATION: THE BIM LEED APPLICATION MODEL DEVELOPMENT By WEI WU A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2010

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2 2010 W ei W u

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3 To m y f amily

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4 ACKNOWLEDGMENTS I would like to give my deepest gratitude to my chair Dr Issa, a great mentor who le ads me into the wonderland of building information modeling, and my cochair Dr Kibert who t eaches me the worlds most beautiful color i s green. I thank my wonderful committee members, Dr. Ries, Dr Olbina and Dr Chow T heir profound knowledge and persistent encouragement navigat e me through one of the most challenging stages in my life. I would like to thank all BCN faculty who I have been fortunately enough to learn from and work with for the last four years. I also want to thank the whole BCN staff team for their willingness to help out. I am indebted to Autodesk for their generosity to authorize me access to the resources that have been invaluable to my research. I want to tell my wife that she is the one and only angel in my life; I want to tell my family how much I love them. W ithout them being there for me, my life is meaningless.

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5 TABLE OF CONTENTS page ACKNOWLEDGMENTS .................................................................................................. 4 LIST OF TABLES ............................................................................................................ 8 LIST OF FIGURES ........................................................................................................ 10 LIST OF ABBREVIATIONS ........................................................................................... 14 ABSTRACT ................................................................................................................... 17 CHAPTER 1 INTRODUCTION .................................................................................................... 19 The Era of New Challenges .................................................................................... 19 Basics of BIM .......................................................................................................... 20 Basics of Green Building ......................................................................................... 21 BIM for Sustainability: the Initiatives ....................................................................... 23 BIM for Green Building Certification: a First Glance ............................................... 25 2 RESEARCH SCOPE .............................................................................................. 28 Identifying the Problem ........................................................................................... 28 Scope of Research ................................................................................................. 31 Research Significance ............................................................................................ 31 3 LITERATURE REVIEW .......................................................................................... 33 Overview ................................................................................................................. 33 Rationale in Green Building Rating System ............................................................ 33 Sustainability Indicators .................................................................................... 34 LEED as the Sustainability Indicator Tool ......................................................... 38 BIM Solution and Functionality Inventory ................................................................ 42 Revit as the BIM Solution ................................................................................. 44 Functi onality Inventory of Revit ........................................................................ 45 Implementing BIM in Green Building Design and Construction .............................. 46 Energy Simulation in BIM ................................................................................. 49 Energy simulation using IES/Revit plug in ........................................ 50 Energy simulation using GBS/Revit plugin ................................................ 53 LEED Water Analysis Using GBS .................................................................... 55 LEED Daylighting and View Analysis ............................................................... 57 BIM for Sustainability: Academic Research ...................................................... 58 Integration Framework Development ...................................................................... 60

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6 Interoperability .................................................................................................. 60 IFC and its support for sustainability .......................................................... 62 XML and its support for sustainability ........................................................ 66 Internalize Sustainability within BIM ................................................................. 67 Code Checking: Sustainability Compliance ...................................................... 68 4 METHODOLOGY ................................................................................................... 71 Overview ................................................................................................................. 71 Feasibility Survey .................................................................................................... 72 Generic Integration Framework .............................................................................. 73 BIM LEED Application Model ............................................................................... 74 LEED Materials and Resources Use Case ............................................................. 76 5 RESULTS AND DISCUSSIONS ............................................................................. 77 Results: Feasibility Survey ...................................................................................... 77 Part 1: General Information .............................................................................. 77 Part 2: Section 1 Perception on Status Quo ..................................................... 81 Part 2: Section 2 Feasibility Analysis ................................................................ 88 Survey Summary .............................................................................................. 92 Results: Generic Integration Framework ................................................................. 93 Interpreting LEED Requirements ...................................................................... 95 Minimum program requirements ................................................................ 96 LEED categories ........................................................................................ 98 Screening the BIM Functionality Inventory ..................................................... 102 Integration Framework Summary ................................................................... 104 Re sults: Revit LEED Application Model ............................................................. 107 Module 1: Design Assistance ......................................................................... 109 LEED strategy and Revit template ........................................................... 110 LEED knowledge and Revit API ............................................................... 111 Mo dule 2: Certification Management .............................................................. 115 LEED calculation using shared parameter ............................................... 118 LEED certification management using web based application ................. 118 Results: LEED Materials and Resources Use Case ............................................. 123 Owners Commitment to LEED ....................................................................... 123 MPRs and Prerequisites ................................................................................. 123 Materials and Resources: Requirements vs. Functionalities .......................... 125 Materials and Resources: Execute Revit LEED Application Model ............. 125 Module 1 execution: design assistance for MR ........................................ 127 Module 2 execution: LEED calculation using phasing and shared parameters ............................................................................................ 129 Module 2 execution: LEED certification management using web application ............................................................................................. 133 Discussion: Code Checking for LEED Certification ............................................... 137

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7 6 CONCLUSIONS LIMITATION S AND RECOMMENDATIONS ............................ 140 Conclusions .......................................................................................................... 140 Limitations ............................................................................................................. 141 Recommendations for Future Research ............................................................... 143 APPENDIX A FEASIBILITY SURVEY OF BIM FOR LEED CERTIFICATION ............................ 145 B DEMO: LEED TEMPLATE IN REVIT .................................................................... 149 C SAMPLE CODES: LEED KNOWLEDGE PANEL ................................................. 151 D DEMO: SHARED PARAMETERS ........................................................................ 154 E DEMO: REVIT TO MYSQL VIA ODBC ................................................................. 158 F DEMO: USE CASE MRC1 AND MRC2 ................................................................ 160 G DEMO: USE CASE MRC3 MRC7 ...................................................................... 164 H SAMPLE CODES: REVIT LEED APPLICATION MODEL ................................. 166 LIST OF REFERENCES ............................................................................................. 176 BIOGRAPHICAL SKETCH .......................................................................................... 181

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8 LIST OF TABLES Table page 3 1 Role and position of indicators in general sustainability framework .................... 36 3 2 Indicators of sustainability in construction .......................................................... 37 3 3 Quick overview of popular BIM software solutions in current market .................. 43 3 4 FC/BIM supported sustainability applications ..................................................... 65 5 1 Applicability levels in Category 1 Sustainable Sites ......................................... 89 5 2 Applicability levels in Category 2 Water Efficiency .......................................... 90 5 3 Applicability levels in Category 3 Energy and Atmosphere .............................. 90 5 4 Applicability levels in Category 4 Materials and Resources ............................. 91 5 5 Applicability levels in Category 5 Indoor Environmental Quality ...................... 92 5 6 Applicability levels in Categories 6 and 7 ........................................................... 92 5 7 Interpreting report of MPR 1 ............................................................................... 96 5 8 Interpreting report of MPR 2 ............................................................................... 97 5 9 Interpreting report of MPR 3 ............................................................................... 97 5 10 Interpreting report of MPR 4 ............................................................................... 97 5 11 Interpreting report of MPR 5 ............................................................................... 97 5 12 Interpreting report of MPR 6 ............................................................................... 97 5 13 Interpreting report of MPR 7 ............................................................................... 98 5 14 Prerequisite interpretation report of SSp1 .......................................................... 99 5 15 Credit (without Option) interpretation report of SSc1 .......................................... 99 5 16 Credit (with Option) interpretation report of SSc2 ............................................... 99 5 17 Prerequisite interpretation report of MRp1 ........................................................ 100 5 18 Credit interpretation report of MRc1.1 .............................................................. 100 5 19 Credit interpretation report of MRc1.2 .............................................................. 100

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9 5 20 Credit interpretation report of MRc2 ................................................................. 101 5 21 Credit interpretation report of MRc3 ................................................................. 101 5 22 Credit interpretation report of MRc4 ................................................................. 101 5 23 Credit interpretation report of MRc5 ................................................................. 101 5 24 Credit interpretation report of MRc6 ................................................................. 102 5 25 Credit interpretation report of MRc7 ................................................................. 102 5 26 Functionality screening for MRp1: Storage and Collection of Recyclables ....... 102 5 27 Functionality scr eening for MRc1.1: Building Reuse Structural ...................... 103 5 28 Functionality screening for MRc1.2: Building Reuse Nonstructural ................ 103 5 29 Functionality screening for MRc2: Construction Waste Management .............. 103 5 30 Functionality screening for MRc3: Material Reuse ........................................... 103 5 31 Functionality screening for MRc4: Recycled Content ....................................... 103 5 32 Functionality screening for MRc5: Regional Materials ...................................... 103 5 33 Functionality screening for MRc6: Rapidly Renewable Materials ..................... 103 5 34 Functionality screening for MRc7: Certified Wood ............................................ 104 5 35 Integration framework summary ....................................................................... 104 5 36 Prepare the Revit LEED application model for MR credits ............................ 126 5 37 Model based calculation for MRc1.1 Building R euse ..................................... 133 5 38 Manual calculation for MRc1.1 Building R euse ............................................. 133

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10 LIST OF FIGURES Figure page 1 1 Project delivery paradigm shift ............................................................................ 26 1 2 Expected growth in BIM use on LEED projects .................................................. 27 3 1 LEED rating systems .......................................................................................... 39 3 2 The user differences in BIM implementation ...................................................... 47 3 3 Frequency of modeling elements with BIM ......................................................... 48 3 4 BIM use in green projects per user group ........................................................... 48 3 5 Integrative BIM and energy analysis platform ..................................................... 50 3 6 The IES plugin interface in Revit .............................................................. 50 3 7 Workflow using IES with Revit ................................................................... 51 3 8 Zonebased modeling floor plan ...................................................................... 52 3 9 Room based modeling floor plan ..................................................................... 52 3 10 IES load calculation report in Revit ............................................................ 52 3 11 Hierarchy diagram of the gbXML schema .......................................................... 53 3 12 Set up project location in GBS ............................................................................ 54 3 13 Design alternative configuration in GBS ............................................................. 55 3 14 LEED water credit calculation in GBS ................................................................ 56 3 15 Con figure plumbing fixture efficiency in GBS ..................................................... 56 3 16 Achieve net zero potable water in landscaping. ................................................. 57 3 17 LEED daylighting assessment module in IES ............................................ 58 3 18 LEED daylighting analysis in GBS ...................................................................... 58 3 19 Facility lifecycle helix .......................................................................................... 61 3 20 Architecture diagram of IFC 2x4 Beta 3 .............................................................. 64 3 21 IFC/BIM supported sustainable construction ...................................................... 65

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11 3 22 CORENET e Plan Check System ....................................................................... 69 4 1 Research workflow. ............................................................................................ 71 4 2 The logic flow of the BIM LEED application model. ......................................... 75 5 1 Companys role in a construction project. ........................................................... 78 5 2 Companys experience with BIM. ....................................................................... 79 5 3 BIM authoring tools used by the respondents .................................................... 80 5 4 Respondents companys experience with LEED NC ......................................... 81 5 5 Current BIM solutions are adequate for LEED NC v2.2 project delivery. ........... 82 5 6 Full integration of BIM in LEEDNC v2.2 project delivery is realized. ................. 83 5 7 BIM is effective in the preconstruction stage of LEED NC v2.2 projects ............ 83 5 8 BIM is effective in the construction stage of LEED NC v2.2 projects. ................. 84 5 9 Current BIM tools can help formulate LEED strategies. ..................................... 84 5 10 Current BIM tools can facilitate the generation and dissemination of design and contract documents. .................................................................................... 85 5 11 Current BIM tools can facilitate communication and information exchange between project members. ................................................................................. 85 5 12 Current BIM tools can facilitate certification documentation generation and submission to LEED Online. ............................................................................... 86 5 13 Current BIM tools can help reduce upfront cost of pursuing LEED NC v2.2 certification. ........................................................................................................ 86 5 14 Cur rent BIM tools can increase the overall chances of achieving LEED NC v2.2 certification. ................................................................................................. 87 5 15 Intuitive relationship of the integration framework. .............................................. 93 5 16 Integration framework relationship developed. (Source: adapted from Biswas et al. 2009). ........................................................................................................ 95 5 17 Execute Revit LEED application model in project delivery. ........................... 109 5 18 The LEED NC 2009 Revit project template ................................................... 112 5 19 Revit, Revit API and Add Ins ............................................................................ 113

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12 5 20 HelloWorld addin ........................................................................................... 114 5 21 Modify Revit.ini ................................................................................................. 114 5 22 Create a LEED project information addin through Revit API ........................... 117 5 23 Architecture of the proposed certification management web application. ......... 121 5 24 Relational tables for the certification management web application ................. 124 5 25 Module 1: Design assistance for MR credits .................................................... 128 5 26 Site plan to demonstrate recycling area for c ompliance with MRp1 ................. 130 5 27 Distance calculator using zip codes for MRc5: Regional Materials. .................. 131 5 28 Use Phasing to attach the time dimension to wall schedules. ...................... 132 5 29 Suggested application model implementation procedures. .............................. 134 5 30 User interface of proposed LEED certification management web application .. 136 5 31 Components and workflow in an IFC based code checking. ............................ 137 B 1 Create new project template in Revit. ............................................................... 149 B 2 Add new Green Building Property into template ............................................. 149 B 3 Create a LEED NC 2009 drawing sheet ........................................................... 150 B 4 Populate the LEED NC 2009 drawing list schedule. ......................................... 150 D 1 Create a new shared parameter file Revit LEED.txt ......................................... 154 D 2 Add desired shared parameters and groups .................................................... 154 D 3 Edit the steel beam family, and modify the Family Types .............................. 155 D 4 Add proper fields into the structural framing material takeoff. ........................... 156 D 5 Completed calculation for the MRc4: Recycled Contents of the sample structural framing. ............................................................................................. 157 E 1 Set up the ODBC export in Revit ...................................................................... 158 E 2 Exported Revit model data in MySQL database ............................................... 159 F 1 Demolish and newly construct in Revit ............................................................. 160 F 2 Completed project floor plan ............................................................................. 161

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13 F 3 Create a Wall Schedule for phase Existing .................................................. 161 F 4 Create wall schedules and assign them different phasing properties ............... 162 G 1 Calculate MRc3 using shared parameter ......................................................... 164 G 2 Calculate MRc5 using shared parameter ......................................................... 165 G 3 Calculate MRc6 using shared parameter ......................................................... 165 G 4 Calculate MRc7 using shared parameter ......................................................... 165

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14 LIST OF ABBREVIATIONS AEC Architecture, Engineering and Construction ANSI American National Standards Institute API Application Programming Interface ASHRAE American Society of Heating, Refrigerating and Air Conditioning Engineers BIM Building Information Modeling BREEAM Building Research Establishment Environmental Assessment Method CASBEE Comprehensive Assessment System for Building Environmental Efficiency CFM Cubic Feet per Minute CIS/2 CIMSteel Integration Standards CLI Common Language Infrastructure DLL Dynam ic link Library DOM Domain Object Model FTE Full time Equivalent FSC Forest Stewardship Council GBCI Green Building Certification Institute GBI Green Building Initiative GBS Green Building Studio gbXML Green Building eX tensible Markup Language GSA General Service Administration GUI Graphical User Interface GUID Global Unique Identifier I/O Input/output

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15 IAI International Alliance for Interoperability ICC International Code Council IDM Information Delivery Manual IES Illuminating Engineering Society IES Integrated Environmental Solutions IFC Industry Foundation Class IFD International Framework for Dictionaries IGCC International Green Construction Code ISO International Organization for Standardization LEED Leadership in Energy and Environmental Design LEED AP LEED Accredited Professional LEEDNC LEED for New Construction LCA Life Cycle Analysis LCC Life Cycle Cost LCGWP Life Cycle Global Warming Potential LCODP Life Cycle Ozone Depletion Potential MEP Mechanical, Electrical and Plumbing MPR Minimum Program Requirements MVD Model View Definition NBIMS National BIM Standards NIBS National Institute of Building Science NIST National Institute of Standards and Technology ODBC Open Database Connectivity PDF Portable Document Format PHP Hypertext Preprocessor

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16 SQL Structured Query Language USGBC United States Green Building Council VOC Volatile Organic Compound WBDG Whole Building Design Guide WAMP Windows, Apache, MySQL and PHP XML eX tensible Markup Language

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17 Abstract of Dissertation Pre sented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy INTEGRATE BUILDING INFORMATION MODELING AND GREEN BUILDING CERTIFICATION: THE BIM LEED APPLICATION MODEL DEVELOPMENT By Wei Wu August 2010 Chair: R. Raymond Issa Cochair: Charles J. Kibert Major: Design, Construction and Planning Building information modeling (BIM) and green building are currently t wo major trends in the architecture, engineering and construction (AEC) industry This research recogniz e s the market demand for better solutions to achieve green building certification such as LEED in the United States. It proposes a new strategy based on the integrat ion of BIM and green building rating systems. The research firstly conducted a feasibility survey to investigat e two fundamental questions in the BIM and LEED integration: 1) what LEED certification requires; and 2) what functionality BIM possess to assist compliance with such requirements Based on the matchup of LEED certification requirements with the functionality inventory of popular BIM software solutions, a framework was then established to prepare the theoretic al foundation for pragmatic solutions t o support this integration. The BIM LEED application model was created to handle practical problems at the credit level that might occur in actual LEED project s. It consisted of two modules: Design Assistance and Certifica tion Management The Design A ssistance module took advantage of the Autodesk Revit API to provide the designers with off the shelf LEED knowledge built

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18 into the BIM software to ensure the design was LEED oriented. The Certification Management module wa s a web application built upon the Apache/MySQL/PHP platform that focused on managing project information, LEED documentation and submittals for the certification purpose. Finally the LEED M aterials and R esources use case was created to preliminarily valida te the application model by simulating the LEED project delivery process. Overall, this research proposed and demonstrated that the BIM LEED integration was feasible with considerable constraints T he integration should accommodate the needs of different team members with specialized assistance at different stage of the project delivery process N ew functionalities of BIM software solutions and better support for information exchange at the database level would facilitate more rigorous implementation of BIM in green building certification .

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19 CHAPTER 1 INTRODUCTION The Era of New Challenges The architecture, engineering and construction (AEC) indus try has been witnessing a boom in building information modeling (BIM) used in parallel with the continuous momentum of the green building movement in the last decade or so. Although quite unrelated concepts at first glance, BIM and green building collectiv ely are able to best address the unprecedented challenges in productivity and sustainability encountered by the AEC industry. Teicholz (2004) noted that in contrast to the overall improvement of productivity in nonfarm industries, productivity in the cons truction industry had actually regressed between 1964 and 2003. Teicholz accounted for this abnormality by identifying the following major causes: A significant portion of the construction business process is classified as nonvalue adding due to the fragmentation of existing business paradigm, and Lack of interoperability in heterogeneous applications of information technology across the industry has exacerbated the situation. Statistics from a 2004 National Institute of Standards and Technology (NIST) research report have confirmed the magnitude of the interoperability issue by providing that the failure to adequately support industry information exchange costs as much as $15.8 billion yearly (Gallaher et al. 2004). On the other hand, the far reaching adverse impacts of the AEC industry on the natural environment have been well documented with the increased public awareness of such impacts. According to the U.S. Green Building C ouncil (USGBC 2009), in the United States buildings alone account for:

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20 72% of electricity consumption, 39% of primary energy use, including fuel input for production, 38% of all carbon dioxide (CO2 40% of raw materials use, ) emissions, 30% of waste output (136 million tons annually), and 14% or 15 trillion gallons of potable water consumption. T he business as usual paradigm that views the environment as an infinite source of materials and energy and a repository for waste is no longer effective to help the industry tackle the challenges posed by the dual demands of increasing the productivity and mitigating the environmental impacts of the built environment New paradigms have been proposed, highlighting the roles of smarter IT applications such as BIM, and more environmental ly conscious practice exemplified by green building design and construction. This research takes one step further to look at the synergy between BIM and sustainability, and seeks a truly integrated business paradigm of the AEC industry i n an era of new challenges. Basics of BIM BIM started to gain popularity at the turn of the new millennium however BIM as a technology is not new to the industry. Terms like building product model, virtual building and intelligent object model have been in use for over twenty years, and they could be perceived as earlier forms of BIM. The development of both the concept and the technology of BIM is contextual and user specific (Eastman et al. 2008). However, it is most important to understand that BIM is not about a simple 3D geometric model or a specific software application. This has been a major misconception in the industry. Jernigan (2007) pointed out that there were two basic formats one could rely on to avoid confusion about building information modeling. The little bim is used to represent applications focused topics, for instance, software packages such as Au todesk Revit

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21 (hereinafter referred as Revit) ArchiCAD, and BentleyBasics of Green Building are bim tools. The BIG BIM is the management of information and the complex relationships between the social and technical resources that represent the complexity, collaboration, and interrelationships of todays organizations and environment. The focus is on managing projects to get the information to the right place at the right time. To help clarify what BIM is, a consistent and official definition of BIM is surely needed. Variou s versions of this definition have been proposed around the world. In the United States, the National Institute of Building Science (NIBS) is one of the leading organizations that conduct research in BIM. They provided the following definition in the first release of the National BIM Standard: A BIM is a digital representation of physical and functional characteristics of a facility. As such it serves as a shared knowledge resource for information about a facility forming a reliable basis for decisions duri ng its lifecycle from inception onward. A basic premise of BIM is collaboration by different stakeholders at different phases of the lifecycle of a facility to insert, extract, update, or modify information in the BIM to support and reflect the roles of th at stakeholder. The BIM is a shared digital representation founded on open standards for interoperability (NIBS 2007) According to this definition, the content of BIM is the shared building life cycle information; its role is to support all stakeholders i n decisionmaking at different phases with reliable project data readily captured; and the basis of such support is the freedom of information exchange empowered by open standards for interoperability. The term sustainability is a legacy of the 1987 Report of the World Commission on Environment and Development (WECD): Our Common Future, which defined sustainable development as development that meets the needs of the present without compromising the ability of future generations t o meet their own needs. Green building

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22 is the contextual implementation of general sustainability principles in the AEC industry. Those principles advocate the regulation of building activities to mitigate impacts on climate change, energy consumption, resource depletion, water conservation, land degradation and biodiversity, to name a few. They also set up a baseline performance for the built environment and promote improvement in indoor environmental quality to promote occupants health and productivity. The final products of practicing sustainability in the AEC industry will be green buildings. In order to efficiently guide the design and construction of green buildings, it is beneficial to have consistent metrics for the quantitative and qualitative evaluation of building performance. These systematic portfolios of metrics are usually known as the green building rating system s Fowler and Rauch (2006) defined green building rating systems as tools that examine the performance or expected performance of a whole building, translating this into an assessment scheme for comparison with other buildings. In the business case, as the demand for more sustainable properties rises up steadily, building owners and developers perceive building green as more than a challenge but rather a promising profit source, as confirmed by the gradual acceptance of green building rating systems in the industry. With recent governmental endorsement and incentives, the green building market has been rejuvenated, making pursuit of certified green buildings become a huge momentum in the market transformation. Currently, the Leadership for Energy and Environmental Design (LEED) is one of the most popular green building rating system s in the United States LEED certification also becomes a thriving business in global green building market.

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23 Other popular systems around the world include BREEAM from the UK, CASBEE from Japan, Green Globes U S (adapted from Green Globes Canada), and SB Tool (formerly known as GB Tool, Canada). A quic k review reveals that the general structure of these rating systems includes (but is not limited to): Assessment targets: building performance and functionality vary significantly according to their types (e.g. office, retailing, residential and school), and stages of their life cycle (e.g. new construction, operation and maintenance). A rating system needs to be specific on which type(s) of buildings it is evaluating and certifying. For instance, the current LEED family includes rating systems of LEED NC ( new construction); LEED EB (existing building); LEEDO & M (operation and maintenance); LEED CS (core and shell); LEED CI (commercial interior); and LEED H (homes); Assessment categories: the assessment categories (often termed credits) address the content s and dimensions encapsulated in the green building design and construction (e.g. energy, water, materials, community and occupant health); set up corresponding performance requirements and metrics; and provide guidelines for compliance; Scoring system: th e weighted scores calibrate the performance of buildings; determine the status of compliance; and cascade the certification awarding tiers; and Documentation requirements: comprehensive documentation is required to facilitate communication; support claim for credit compliance; certification review and award. BIM for Sustainability: the Initiatives When looking into the paradigm shift in the green building movement and the t ransition to building information modeling, professionals with dual expertise tend to think about possible synergies between them. It makes better sense when breaking down the project delivery of a green building. For instance, most mainstream BIM authoring tools today have built in functionalities needed to configure building performance through simulation (e.g. energy, day lighting and thermal comfort). So at the very beginning of the project delivery, the owner and the project team will be able to embark on sustainability assessment Later on, with all design information stored in a

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24 centralized and integrative building information model, the project team will have a reliable data resource to facilitate that all sustainability goals will be realized in the construction process, passed on to facility operation and maintenance and eventually to facility deconstruction. Because of the flexibility of information exchange, the stakeholders can continuously update the BIM to monitor and manage the building perform ance. In such a manner, the building is truly green and sustainable from a life cycle perspective. At this moment, substantial attempts to integrate building information modeling with sustainability have been championed by software companies including Aut odesk, Graphisoft, Bentley and Digital Project. Autodesk as far back as 2005 published a whitepaper on Building Information Modeling for Sustainable Design, and similar initiatives have been instituted by other abovementioned companies. Meanwhile, in academia efforts have been undertaken with emphasis on technological support of this integration established on the empirical evidence from successful case studies in the industry. A possible approach to boost BIM application in sustainability is to create th e integration of green building rating system s into current BIM authoring software. This will help project team s make more informed decisions at the early design stage to accommodate sustainability goals, and potentially generate the optimum impacts with t he least cost. As soon as construction starts, the sustainability embedded building information model evolves with newly generated field data and updates to maintain the project s focus on sustainability. More importantly, developers nowadays typically would like to be acknowledged for building green for instance, obtaining LEED certification

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25 for their projects. Integrating the green building rating system with the building informatio n model, will give that project a better chance to achieve the desired certification. BIM for Green Building Certification: a First Glance Compared with traditional CAD applications, BIM stands out with its intelligence enabled by object based parametric m odeling. According to Eastman et al. (2008) such intelligence typically includes: Conflict detection: 3D parametric modeling systems will take into account spatial interferences between objects and automatically update the layout to avoid them, if relevant rules have been predefined and embedded in them; Topological structures: topological connections answer questions like what can be connected; what the connection consists of; and how the connection is composed in response to various contexts. Topology and connections are critical aspects of BIM tools that specify what kind of relations can be defined in rules; Property and attribute handling: properties and attributes of objects supplement information other than geometry or topology, but provide useful dat a for objects to be analyzed, priced, and procured by other applications. These are critical information needed in the real world project delivery process and are missing in current 2D based practice. Current BIM authoring tools default to a minimal set of properties for most objects and provide the capability of adding extendable sets; and Consistent drawing/documentation generation: with BIM, each building object instanceits shape, properties, and placement in the model is defined only once, and because of the nonredundant building representation, all drawings, reports and analysis datasets are consistent. This capability alone resolves a significant source of errors and guarantees internal consistency within a drawing set. For professionals participating in green building projects, these features are highly valuable. In order to fulfill the requirements of green building rating systems such as LEED, documenting the building information is the key being successful Figure 11 A describes the current indust ry complexity of information generation and exchange among project team members. A major drawback in this paradigm is due to the lack of a centralized information source for the project. This fragmentation and inconsistency

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26 make this process error prone, and the redundancy causes loss of efficiency, cost overrun, or even potential failure of the project delivery In contrast, a fully developed BIM model synthesizes the full range of project information as shown in Figure 11 B Conceivably this model will al so capture the particular information required for green building certification in addition to providing better quality construction documents. More importantly, with this highly integrative model, project team members can access the model and extract information from a single reliable source. Such a BIM (information) centric paradigm consistently keeps the whole project team on the same page, and significantly reduces change orders or rework due to erroneous project information. As expected a process relyi ng on this paradigm will raise the profitability of green building projects and eventually increase the chances of accomplishing the desired level of green building certification. A) Documentationcentric model. B) Informationcentric model. Figure 11. Project delivery paradigm shift (Source: Sjgren 2007). Given that fact that very few green projects today have BIM involved, professionals especially experts in BIM and green buildings see the impacts of BIM

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27 increasing on the horizon. As a matter of fact, according to the most recent SmartMarket Report published by McGraw Hill Construction (2009), North American AEC professionals believes that BIM will be highly valuable in producing better performing buildings, and expect high increase in use of BIM on LEED projects (Figure 1 2) in the North American building market. Figure 1 2. Expected growth in BIM use on LEED projects. (Source: McGraw Hill Construction 2009).

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28 CHAPTER 2 RESEARCH SCOPE Identifying the Problem In the North American building market, a very meaningful case for the BIM and green building integration to look at will be the implementation of BIM in the LEED certification process. Due to governmental endorsement and strong marketing of the U.S. Green Building Council (USGBC), LEED certification has become a thriving business paradigm in promot ing sustainability in the AEC industry T he debate over LEED on whether it is a scientific system continues but professionals do acknowledge its positive impacts on leading the industrys transition to green. I n light of the LEED system, USGBC along with ANSI ASHRAE and IES has published a new standard that defines the minimum requirements for a highperformance green building. The ANSI/ASHRAE/USGBC/IES Standard 189.12009 for the Design of HighPerformance Green Buildings except Low Rise Residential Buildings recently became a jurisdictional compliance option in the Public Version 1.0 of the International Green Construction Code published by the International Code Council. The IGCC regulates construction of new and remodeled commercial buildings, and Standard 189.1 serves as a technical backbone of it (ASHRAE 2010) In addition, many corporate investors perceive the pursuit for LEED certification for their assets as a public relation move to set their business apart from competitors in the market The challenge to achieve LEED certification is well acknowledged in terms of the technology intensity, extra costs and cumbersome documentation management. Experience is indisputably critical given the fact that the LEED rating system is not fully written in plain language. Project teams often find it difficult to understand what exactly

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29 USGBC requires for a specific credit, and end up having to file a CIR (credit interpretation request) to find out. Such requests are always associated with a nontrivial cost, exacerbati ng the already tightened budget in todays market. Even worse is the documentation part. As introduced in the overview of green building rating systems, LEED has a credit/point structure and carries a scoring system to evaluate a buildings performance in determining its compliance with these credits requirements. Basically, other than actual field inspection, the official review of USGBC is mostly paperwork based. The project team has to submit a considerable amount of documents in a strictly controlled f ormat (LEED templates) through a special system (called LEED Online) administered by the USGBC. Apparently, the quality of the documentation and the ease of generating the required LEED documentation are of direct interest and critical importance to the success of a LEED project. With the LEED certification having been practiced in the market for over a decade, project teams have gained substantial experience to deal with USGBC and the LEED system. Creative strategies have been thought out to improve productivity in the LEED project delivery. Noticeably, the peripheral businesses that provide services to LEED documentation management are booming at the same time. Outsourcing the documentation part to those 3rd party solution providers becomes quite popular. Nonetheless, this outsourcing approach might prove to be problematic. A major concern here is on the integrity of project information in communication between the project team and the contracted 3rd party documentation agent. By involving extra personnel and introducing more fragmentation into the LEED process, chances of making even more mistakes in data collection and documentation preparation are simply higher.

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30 Unfortunately, in fear of the tedious process of compiling the required LEED documentation, m ore than a few project teams have opted to take the risks anyway and try to make certain tradeoffs in profitability afterwards. The advent of BIM technology, especially with anecdotal evidence of its implementation in green projects spreading in the indus try, has caused professionals to start envisioning the integration of BIM and LEED certification process. According to Eastman et al (2008), BIM is capable of capturing project information and generating documentation. With special care taken on the softw are side, an enhanced BIM application could potentially resolve what usedto be obstinate problems in LEED project delivery, for instance, dealing with the complexity of conducting full building energy simulation, acoustical analysis, and daylighting desig n. The scenario that project teams can click some magical BIM button and will be able to comply with all pursued LEED points meanwhile accomplish all dreary tasks of compiling the LEED project documentation is not yet realistic at this moment In regards t o leverage a green building project delivery with BIM, particularly when the eventual goal is to achieve a certain credential such as LEED certification, some of most critical outstanding issues will include: How to interpret the requirements of the rating system (at the credit level) into requests for data; What desirable functionalities BIM applications should possess to generate the requested data; What if scenario when the desired functionalities are not yet available; and How to facilitate project management using BIM and green building integration. When studying the North American building market, the rating system in the above list has to be the LEED green building rating system, and the major BIM application

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31 software will be Revit from Autodesk based on market share statistics (McGraw Hill Construction 2008). Scope of Research This research attempts to look at the integration of BIM and green building from a systematic perspective, using the LEED rating system and the LEED certification as a unique case. An important assumption for this research is that there is a market trend to adopt BIM in the green building delivery and certification process. In response to the problems as identified in previous paragraph, it is the primary objective of this study to propose a solution to those issues: Objective I: Investigate the feasibility of the full scope integration of BIM and LEED rating system; Objective II: Create and develop the generic framework for this integration based on the matchup of the prescribed LEED credits requirements and the functionality of Revit; Objective III: Identify the gaps in the framework where no existing functionality is available to help compliance with certain LEED credits, demonstrate development of functionality extensions through the application programming interface (API), and make constructive recommendations; Objective IV: Look into the project management aspect of this integration, and provide an applicable solution to LEED certification with emphasis on documentation compiling and management; and Objective V: Develop the BIM LEED application model and preliminarily validate it through the use case of Materials and Resources category. Research Significance The AEC industry is in the midst of transition to a new business paradigm, green building and BIM will continue to be the hotspots during this paradigm shift. As new technology emerges and is updated almost on a daily basis, the expectation from clients on building projects balloons simultaneously. The demand for high performance

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32 buildings will predictably ascend as more public and private investment pours in to the market. To tackle those challenges, integrating BIM and green building needs to be pursued. The fundamental contribution of this research will be the unique approach it proposes to fulfill green building certification such as LEED by integrating functionalities of BIM It conducted a comprehensive literature review (Chapter 3) to explore the theoretical foundation, and created a comprehensive integration framework to guide and foster practical innovation. It demonstrated the integration by looking at the most popular green building rating system: LEED and the most prevailing BIM software: Autodesk Revit. The informationcentric project management solution illustrates an optimized workflow in LEED certification that outperforms conventional approaches. As a whole, the BIM LEED application model makes an ambitious effort to provide professionals with an off theshelf tool to facilitate the actual LEED project delivery process (Chapter 5) With further validation and improvement, the application model could be developed into a real product to be used by LEED project teams. Recommendations ( Chapter 6) w ere also made to future research that could contribute to the steady advancement in BI M and green building integration.

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33 CHAPTER 3 LITERATURE REVIEW Overview This chapter reviews the literature in relation to the primary research objectives. An a nalysis of the rationales inside the green building rating systems helps interpret the data requirements embedded in the prescribed rating criteria (requirements). A close look at current major BIM solutions summarizes the inventory of available functional ities to support sustainability. Analysis of the empirical evidence of BIM application s in green building projects fosters the assumption in pursuit of the integration. The undergoing endeavors in the integration framework will provide reference to more intensive development for the use case in BIM and LEED integration. Rationale in Green Building Rating System The principles of sustainable development define the ecological, economic, social and cultural framework for the activities of communities, enterprises and individual citizens (Hkkinen 2007). The construction industry and the built environment are key areas if human beings are to attain a sustainable development of societies as stated in CIB Agenda 21 on sustainable construction (CIB 1999). Accordi ng to the UNEP's vision (2006) for sustainability in the building and construction sector: Buildings are routinely designed and maintained to be optimized over their entire life span; Legislation and building standards include sustainability considerations and requirements; Environmental aspects are normally considered in any building and construction project and include short term as well as long term aspects; Policies and incentives provided by the government support sustainable building and construction practices; and

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34 Investors, insurance companies, property developers and buyers/tenants of buildings are aware of sustainability considerations and take active role in encouraging sustainable building and construction practice. Most of c urrent green building rating systems are not formal standards or building codes They are consensus based voluntary programs, and sometimes professionals have conservative opinions about them for lack of scientific foundations For instance, despite of the prevalence of LEED in the U.S., it has been criticized for unjustified weighting of points allocated to each environmental categor y by many professionals in the AEC industry. Udall and Schendler (2005) developed a comprehensive critique of the defects and flaws of LE ED in guiding green building development. Recent revision of LEED has reflected dedication to resolving such problems. A step further is that some green building standards have been developed on the basis of these green building rating systems, for instanc e, the ANSI/ASHRAE/USGBC/IES Standard 189.1 2009 (ASHRAE 2010) based on LEED and the ANSI/GBI 012010 (ANSI 2010) based on the Green Globes The scope of the sustainability framework is enormous. In the context of the AEC industry alone, the immensity of issues that should be addressed to efficiently promote sustainability in the built environment seems overwhelming. Carefully adopting the criteria to guide green building design and construction is thus an ongoing task for all stakeholders in the industry. Sustainability Indicators Sustainability indicators integrate environmental, social, and economic factors so that the complex cause and effect relationships between these multiple factors can be more readily investigated (Guy and Kibert 1998). Indicators are needed to precisely define sustainability criteria and to measure the performance of the construction

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35 industry and the built environment. Decisionmakers and policy makers need indicators to evaluate economically viable and technically feasible strategies to improve the quality of life, while at the same time increasing resource use efficiency. Numerous actors in the construction and development process need tools and guidelines based on indicators to improve current practices and the quality of constr uction (CRISP 2002). Agenda 21, Chapter 40 states that Indicators of sustainable development need to be developed to provide solid bases for decision making at all levels, and to contribute to a self regulating sustainability of integrated environmental and development systems (CIB 1999). Hence the development of sustainability indicators should follow criteria such as: Relevance: clear link to a goal and an objective of sustainability; Objectivity: based on reliable information; Accessibility: appropriate data exist and are accessible; Readability: understandable for a project team and community; Measurability: quantifiable data extraction and interpretation; and Sensibility/Responsiveness: fast and efficient track of changes (Guy and Kibert 1998). The dedication to the identification and creation of scientific sustainability indicators has become a global phenomenon. The International Organization for Standardization (ISO 2006) published the pilot technical specification: ISO/TS 219291, Sustain ability in Building Construction Sustainability Indicators Part 1: Framework for the Development of Indicators for Buildings, in order to standardize the process of defining a framework for sustainability indicators of buildings, and give guidelines for the development and selection of sustainability indicators related to buildings.

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36 The European Commission launched a comprehensive research project named CRISP: A European Thematic Network on Construction and City Related Sustainability Indicators in 1999 as a 3year network gathering 24 members from 16 countries, dealing with Construction and City Related Sustainability Indicators. It brought together the work of a carefully selected set of 24 skilled teams that brought to the network the results achieved in a wide range of national and international projects in this field from across the breadth of Europe. The major deliverables of this project included: The national stateof the art reports; The collection of recent and ongoing R&D works in different countries; The CRISP indicator database (available at http://crisp.cstb.fr/database.asp ); The public Website ( http://crisp.cstb.fr ) gathering all these elements (CRISP 2002). The CRISP project also defined the role of sustainability indicators in the general sustainability framework (see Table 31), especially under circumstances when these indicators were used in combination at the regional or project level, which is exactly how a green building rating system such as LEED was executed. Table 31. Role and position of indicators in general sustainability framework (Source: Adapted from CRISP 2002) Definition Description Sample Value Goal A broad statement that defines the ultimate condition desired Maximize the diversion of all waste from disposal Objective A desired direction of change Reduce the generation of solid waste at source Indicator A variable which helps to measure a state or a progress towards an objective Per capita disposal (kg/person/year) Performance Target A desired level of performance 200kg/person/year Tool A pertinent use of several indicators and performance targets in relation to local conditions and specific uses LEED/BREEAM

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37 In the U.S. market, Guy and Kibert (1998) reviewed the experience in developing indicators of sustainability, and discussed the two major frameworks being used for sustainable efforts at the community level: Local Agenda 21 and the Healthy Communities Ini tiative. Kibert (1994) also inspected the concept of sustainable construction a term often juxtaposed with green building and defined it as the design and operation of a healthy built environment based on resource efficiency and ecological principles. Kibert and Guy (1998) also made the pioneering efforts in proposing methods for the development and selection of indicators for sustainable construction (Table 32), and commented that: Indicators of sustainable construction consider linkages to the greater community while addressing the specific issues of planning, architecture, construction operations, operation and building reuse and adaptation, and final disposalBest practices of indicators selection use a combination of environmental, economic, and social factors in an integrative fashion. Critical indications of sustainable construction will focus on issues such as diver sity and density of land use including urban agriculture, and functioning urban natural ecosystems (Kibert and Guy 1998) Table 32. I ndicators of sustainability in construction (Source: Guy and Kibert 1998) Land Water Materials Energy Use Toxins Brownfi eld land developed annually as a percent of identified sites Total impervious surface and/or impervious surface area per unit area Tons of C&D wast e recycled per unit area of new construction Automobile accidents per selected intersections Smoke free interior environments as percent of total construction Area of green space per building square feet Per capita water consumption Number of historic structures Percent of total electricity consumption from renewable resources Inventory of tree cover Consumption of recycled / reclaimed water per capita Percent of commercial buildings with inhouse recycling Ratio of land area to perimeter distance of the municipality

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38 LEED as the Sustainability Indicator Tool LEED or other equivalent green building rating systems encompass a collection of sustainability indicators to holistically assess building performance, or more accurately, how green the building is. The selection of these indicators does not need specialized knowledge since the issues c onfronting the industry are straightforward and well understood by the professional community, and to a certain extent the general public. As the context varies, rating systems in different countries tend to give priority to certain indicators but the general scope is quite consistent. These sustainability indicators embedded in current major green building rating systems address issues in land degradation, biodiversity, water shortage, energy efficiency, renewable energy, carbon emission, air pollution, materials and resources, indoor environmental quality, to name a few. This research is focused on the North American market, thus the sustainability indicators used by the LEED rating system is of immediate importance to this research. LEED is a third party certification program and a nationally accepted benchmark for the design, construction and operation of high performance green buildings. The USGBC introduced the first LEED green building rating system in 1998 as LEED for New Construction (LEEDNC). Then new systems were introduced and LEED became a portfolio (Figure 31), and kept evolving over time. The current version is LEED v3.0, which consists of three major parts: LEED 2009 version of all rating systems, including New Construction, Core and Shell, Commercial Interior, and Schools, etc; LEED Online v3 (a webbased tool LEED project teams use to manage the LEED registration and certification processes); and Certification Model (an expanded certification infrastructure based on ISO standards, administ ered by the Green Building Certification Institute (GBCI) for improved capacity, speed and performance).

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39 LEED has two key fundamental attributes. First it was developed with an open consensus based process, with input from a broad range of building indust ry professionals and other experts, including the U.S. Department of Energy. Second and common to the other rating systems, using LEED is voluntary. One of the goal s behind creating the LEED system was to establish a measurement standard for what is considered a green building, comparing them on an even playing field. At the time of creation, some U.S. practitioners were finding it difficult to decipher the claims of their competitors and building product manufacturers who also had started campaigns about h ow environmentally conscious their products or buildings were (Krygiel and Nies 2008). Figure 31. LEED rating systems. (Source: USGBC 2008) According to USGBC (2008 ), LEED is intended to provide building owners and operators with a concise framework for identifying and implementing practical and measurable green building design, construction, operations and maintenance solutions, using strategies aimed at improving performance across all the metrics that matter most: energy savings, water ef ficiency, CO2 emissions reduction, improved indoor

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40 environmental quality, and stewardship of resources and sensitivity to their impacts. Taking LEED NC 2009 for example, under this rating system, buildings are evaluated against five major environmental ca tegories An additional category, Innovation in Design, addresses sustainable building expertise as well as design measures not covered under the five environmental categories. Regional bonus points are another feature of LEED and acknowledge the importanc e of local conditions in determining best environmental design and construction practices. A n overview of these categories is listed below : Sustainable Sites (SS, 1 prerequisite, 8 credits, 26 points) Water Efficiency (WE, 1 prerequisite, 3 credits, 10 poi nts) Energy and Atmosphere (EA, 3 prerequisites, 6 credits, 35 points) Material and Resources (MR, 1 prerequisite, 7 credits, 14 points) Indoor Environmental Quality (IEQ, 2 prerequisites, 8 credits, 15 points) Innovation in Design (ID, 0 prerequisite, 2 c redits, 6 points) and Regional Priority (RP, 0 prerequisite, 1 credit, 4 points) In order to get LEED certified, the project has to satisfy the minimum program requirements (MPR, effective from the LEED v3), all the prerequisites and a minimum of 40 point s. If the project goes beyond 40 points, it will be certified as Silver (when achieving 5059 points), Gold (when achieving 6079 points) or Platinum (when achieving 80+ points). A stepby step guide for the project certification is available at the GBCI s website ( http://www.usgbc.org/DisplayPage.aspx?CMSPageID=64). To determine if the project meets these credits requirements, and how many points the project has actually attained, USGBC requires comprehensive documentation for review. The documentation includes two major parts: Compulsory documentation: this includes the official LEED Online templates created specifically for each LEED credit, and other critical project submittals that apply to any building project delivery. The project team has to fill the LEED templates and submit them through LEED Online.

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41 Supplemental documentation: this includes any other materials that the project might feel helpful to achieve a certain point. Typical ly this type of documentation is submitted as attachments to the compulsory documentation. USGBC seldom conducts field inspection to verify the documentation submitted by the project teams due to their belief in professional ethics. This makes the quality and comprehensiveness of the submitted documentation very important for the project team to achieve the targeted points. By carefully reviewing the credit requirements prescribed in the official guidelines (called LEED reference guide, each rating system has its corresponding reference guide compiled by USGBC and project teams have to purchase them), the project team works extremely hard to probe and prepare the information that would fit into the criteria of the reviewers from GBCI. With the LEED Online templates, it should be straightforward for the project team to know what information and data they should provide to USGBC. The real challenge is how to obtain the information and data. Traditional project documenting methodology migh t still apply, but chances are that the specific LEED requirements need extra treatment that goes beyond the scope. A simple example will be meeting the requirements of Materials and Resources Credit 4: Recycled Content (MRc4, this type of abbreviation is accepted in the industry, and will be used hereinafter in this dissertation. To display credits in other categories, simply change the MR to SS or WE, etc. The letter c stands for Credit. When the letter p is used, it stands for Prerequisite). In o rder to achieve MRc4, the project team needs to demonstrate that a certain percentage of the materials used in the project are recycled. Extra work will be needed to keep a record of all the materials that have recycled contents, using the formula provided by the reference guide to compute the dollar value, and finally to come up with the actual percentage of the total material costs. Some of the LEED credits are

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42 cumbersome to achieve. Conceivably, this significantly increases the overhead associated with t he project budget, and potentially it will hurt the project s profitability. To overcome these barriers the project team needs both experience and tools to accurately interpret the LEED credit requirements and understand what data to collect to show compl iance with these requirements. The efficiency of generating, collecting, processing and verifying the desirable information is at the heart of the successful delivery of a LEED project. BIM implementation can substantially facilitate this process. BIM Sol ution and Functionality Inventory There are two major types of BIM solutions in the market, depending on the functionality and intended application environment. One is called BIM authoring solution and the other, BIM auditing/analysis solution. The BIM aut horing tools are often large and robust applications mostly used by design firms to create and compile most of the information contained in a building information model. While the BIM auditing and analysis tools are typically designed to specialize in part icular areas, and used by either design firms or contractors to perform energy analysis, sustainable design analysis, code compliance, construction cost estimate, constructability analysis and construction sequencing (Smith and Tardif 2009). The functional and performance capabilities of different BIM solutions (termed as Functionality Inventory in this research) are relative and contextual since there is no single platform that will be ideal for all types of projects. Table 33 lists some of the most popul ar solutions in the current market, according to McGraw Hill Construction (2008). Beyond the popularity factor, companies should base their decision making process of what BIM software solution to procure on their business needs, company core competence, project type, budget and IT sophistication level. Smith and Tardif (2009)

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43 insightfully pointed out that the selection of the most appropriate software solutions for individual firms should be based on one criterion and one criterion alone: to enhance the revenuegenerating potential of the company. This requires the decisionmakers to take a renewed investment based view, instead of the traditional cost based view, of technology such as BIM. The advantage of an investment based view stems from the realizatio n that the real value of BIM to any organization laying in leveraging the structured information contained in a building information model to create value. Table 33. Quick overview of popular BIM software solutions in current market (Source: Eastman et al 2008; Smith and Tardif 2009) Features Revit Bentley Vico ArchiCAD Solution Type Authoring; partial auditing and analysis Authoring; partial auditing and analysis Authoring; partial auditing and analysis Authoring IFC Certified Yes Yes Yes Yes Operating System Windows Windows Windows Windows and Mac OS X ODBC Support Yes Yes Un known Yes Supported Interfaces DGN, DWG, DWF, DXF, SAT,SKP, gbXML, AVI, BMP, JPG,TGA, TIF and API Primavera, STTAD, RAM, DGN, DWG, DXF, PDF, STEP, IGES and STL Primavera MS Project, Revit, Tekla, ArchiCAD, DXF, DWG, PDF, VRML and JPG CIS/2, SDNF STEP DWG, DXF, VRML, STL, HOOPS, SAT, 3DXML and IGES Strengths Market leader, user -friendly, direct link interfaces, excellent object library, multi -user interface and bi directional drawing support Almost full AEC modeling tools, support complex curved surfaces, support developing parametric objects, provide scalable support Best contractor oriented tool, first real 5-D support. Direct support for Revit, Tekla, Primary and ArchiCAD. Complete project management. Oldest tool, intuitive interface, easy to use, large object libraries, rich supporting application, only strong BIM tools for MACs Weakness Limitations on parametric rules dealing with angles and does not support complex curved surfaces Large and non integrated user interface, heterogeneous functional modules include different object behaviors Complex package of highly specialized modules, expensive, sharp learning curve. Limitations on parametric modeling, not supporting update rules between objects and scalability issue

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44 Revit as the BIM Solution In the U.S. market, the Autodesk Revit (hereinafter referred to as Revit) suite (including Revit Architecture, Structure and MEP) is the most prevailing BIM solution. Before Autodesk acquired Revit, their market leading product AutoCAD was the most successful CAD application in the world. Revit is the specialized solution for th e BIM era. Meanwhile, through research and development, partnership and continuous buyout, Autodesk currently provides a portfolio of highly integrated BIM solutions to the AEC industry, including software applications in addition to Revit, such as EcoTect (conceptual energy simulation, lighting and daylighting design, acoustical simulation ), Autodesk 3ds Max (visual design), Green Building Studio (energy simulation, water consumption design and LEED daylighting design) and Navisworks (clash detection, constructability analysis, sequencing). The dominance of Autodesk products has driven the development of peripheral applications on the common Autodesk platform to proliferate. To some extent, the centralization of BIM solutions may contribute to improving the interoperability in a firms business operation. Other software vendors such as ArchiCAD, Bentley and Vico all have loyal customers, mostly due to the particular feature preferences they have for those applications. For the purpose of this research, Rev it is selected as the core BIM solution tool, supported by supplementary in house software applications from Autodesk. Major considerations contributing to the decision to select Revit include: Availability to academia: Revit is free to academia offered by Autodesk through the online Student and Educator community; User Interface: Revit uses an interface similar to AutoCAD, which is very convenient for previous Autodesk CAD users;

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45 Software Support: Autodesk hosts an enormous amount of Revit tutorials and cu rriculum online and gives free access to students and faculty; Customer Service: Autodesk Revit educators provide responsive feedbacks regarding technical or application questions to users, and they have comprehensive collaboration with the academia; Inter operability: Revit is IFC certified and supports IFC import/export; it also supports ODBC which enables flexible data extraction; Extensibility: Revit has numerous useful plugins and extensions available that fit in very well for this research, besides it has a comprehensive API guide for developers; and Impacts: Revit is a major player in the current BIM tool authoring market, and research using Revit tends to have a greater impact on the market. Functionality Inventory of Revit Revit as a BIM authoring tool possesses powerful functionalities to enable the creation of a comprehensive building information model consisting of the full spectrum of building systems including architectural, structural and MEP components. More importantly, every schedule, draw ing sheet, 2D view, and 3D view created in the Revit environment is derived from a single foundational database, automatically coordinating changes across all facets and presentations as the project develops and evolves (Autodesk 2009). The inventory of ma jor functionalities of Revit in terms of BIM and green building design is summarized as follows: Bidirectional Associativity: A change anywhere is a change everywhere. In Autodesk Revit Architecture, all model information is stored in a single, coordinated database. Revisions and alterations to information are automatically updated throughout the model, which significantly reduc es errors and omissions; Schedules: Schedules provide another view of the comprehensive Autodesk Revit model. Changes to a schedule view are automatically reflected in all other views. Functionality includes associative split schedule sections and selectable design elements via schedule views, formulas, and filtering; Material Takeoff: Calculate detailed material quantities using the Revit Material Takeoff function. Ideal for use on sustainable design projects and for precise

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46 verification of material quantities in cost estimates, Material Takeoff significantly smoothes the material quantity tracking process. As projects evolve, the Autodesk Revit Architecture parametric change engine helps ensure material takeoffs are always up to date; Interoperabilit y: Interoperability enhancements enable users to work more efficiently with members of the extended project team. Users can export the building model or site, complete with critical metadata, to AutoCAD Civil 3D software. They can also import accurate, dat a rich models from Autodesk Inventor software, efficiently speeding time to fabrication. With support for IFC, seamless information exchange between Revit and other critical software application in the project delivery could be realized; and Support Sustai nable Design: Revit supports sustainable design processes from the earliest stages. It exports building information, including materials and room volumes, to the green building extensible markup language (gbXML). Energy analysis can be performed using Autodesk Green Building Studio webbased services, and building performance can be studied using Autodesk Ecotect software. Autodesk 3ds Max Design software can be used to evaluate indoor environmental quality in support of LEED IEQc8.1 (Daylight and Views) certification (Autodesk 2009). Implementing BIM in Green Building Design and Construction Building design and construction are systematic and dynamic. The different building systems are physically and functionally interconnected. Use of modern mechanical, el ectrical, plumbing (MEP) system and building automation system (BAS) has exponentially increased the complexity of the building industry. Meanwhile it stimulated the specialization of industry trades, which indirectly resulted in the fragmentation of the project delivery process. Promoting sustainability thus has to inevitably deal with these various and interdependent building systems, ideally in a holistic manner. With the increased use of BIM, complex process es and analyses that were previously too labor ious or expensive to perform have be en significantly facilitated (Autodesk 2005). The implementation of BIM technology in the construction industry is comprehensive. As noted by the McGraw Hill SmartMarket Report (2008) major players

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47 including owners, architects, engineers, and contractors have all embarked on the initiatives Figure 32 shows the different level of BIM involvement per user, and Figure 3 3 shows the major modeling elements with BIM in the industry. In regard to the actual involvement in green projects, Figure 34 shows an overview of the commitments to sustainability per user group. The expectations, also from the current BIM users, in the development of additional analysis tools concentrated in certain areas are: 50% indicated that LEED calculation software integrated with BIM would be very helpful; 47% thought that more building product content with data about the products sustainability characteristics should be integrated into BIM tools; and 44% believe energy analysis software should be integrated with BIM. To be more specific, the following sections review exemplary BIM implementation intended for sustainability in the AEC industry. Energy simulation, water, daylighting and views were major focuses of such implementation. Figure 32 The user differences in BIM implementation. (Source: McGraw Hill Construction 2008).

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48 Figure 33. Frequency of modeling elements with BIM. (Source: McGraw Hill Construction 2008). Figure 34. BIM use in green projects per user group. (Source: Mc Graw Hill Construction 2008).

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49 Energy Simulation in BIM Energy simulation is an established and critical requirement in the design of sustainable building s. Simulation tools like EnergyPlus, DOE 2, and Energy 10 were developed long before BIMs prevalence. What BIM brought to energy simulation was really an integrative interface that provided the designers a more reliable and consistent building information m odel for analysis, leading to more accurate simulation results. The biggest advantage of parametric modeling rests in its capacity of updating building information simultaneously with the changes made to the model configuration. In the conceptual design st age, architects and designers could test different design alternatives to find the optimal solution. T he adoption of BIM in the early stages of design is crucial in order to exploit its benefits (Schlueter and Thesseling 2008). As one of the first official institutions requiring BIM the U.S. General Service Administration (GSA) leveraged BIM for the submission of mayor projects for final concept approval. With the use of BIM, the GSA encouraged accurate energy estimates in the design process strengthenin g the adoption of BIM from the early design stages on (GSA 2008). Newly emerged simulation tools like Integrated Environmental Solution (IES Virtual Environment) and Green Building Studio (GBS) are able to conduct comprehensive building performance analysis, including energy simulation. IES and GBS both have direct interaction with mainstream BIM authoring tools such as Revit. Unlike conventional simulation tools that rely heavily on manual data input, IES and GBS obtain building data input with inform ation directly extracted from the established building information model.

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50 Energy simulation using IES/Revit plugin IESs specially developed Revit plugin Toolbar (Figure 35) allows performance analysis and BIM within the same platform (Figure 36). Once the building information model is set up, the user can access the different IES performance analysis products by clicking the relevant button. Each product offers different levels of functionality. The data generated by IES' software can be used, for example, to demonstrate to the client why different design options have been chosen, quantify the energy savings expected and aid in the design of building management systems (Figure 37, IES 2009). Figure 35. Integrative BIM and energy analysis platf orm. (Source: IES 2009). Figure 36. The IES plugin interface in Revit. (Source: IES 2009).

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51 Figure 37. Workflow using IES with Revit. (Source: IES 2009). IES conducts energy simulation in two major forms: zonebased modeling and room based modeling. The user may implement one of them or both depending on the stages of the project development and the actual requirements in regard to the simulation results: Zonebased modeling fits best in conceptual design when floor plan details are not yet developed. It groups spaces with similar thermal conditioning requirements into zones, taking into account solar orientation, occupancy, lighting and equipment loads to estimate the approximate energy consumption (Figure 38). Room based modeling is t he concept of modeling and defining each Room as its own thermal zone. It is best during later phase of the project when the design is close to final, since all the information are in the model, it allows for a more accurate building performance analysis (Figure 39). The reporting function of IES is dedicated to presenting a detailed summary of the energy loads per user defined zone or room, categorized into cooling and heating, and air flow, based on the input data extracted from the building infor mation

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52 model and the user definition. Figure 310 provides an excerpt of such report generated by the IES plug in in Revit. Figure 38. Zonebased modeling floor plan. (Source: IES/Revit 2010). Figure 39. Room based modeling floor plan. (Source: IES/Revit 2010). Figure 310. IES load calculation report in Revit. (Source: Model courtesy of Autodesk)

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53 Energy simulation using GBS/Revit plugin The link between the Revit platform and the Green Building Studio web service (Autodesk 2008), now an Autodesk product, has been streamlined through a plugin that enables registered users to access the service directly from their Revit design environment. A key step triggering the conversation between the Revit model and the GBS analysis engine requires the use of gbXML (Green Building eXtensible Markup Language). The Green Building XML schema was specially developed to facilitate the transfer of information from building information models to integrate with design/energy performance analysis (gbXML 2009). A gbXML document organizes information according to the following hierarchy: Location, Building, Space, Surface and Opening (see Figure 311). Figur e 311. Hierarchy diagram of the gbXML schema. (Source: IES/Revit 2010). Based on the buildings size, type, and location (which drives electricity and water usage costs), the webbased GBS determines the appropriate material, construction,

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54 system and equi pment defaults by using regional building standards and codes to make intelligent assumptions (Figure 312). A handy function of GBS supports design alternative analysis. Using simple dropdown menus, architects can quickly change any of these settings to define specific aspects of their design; a different building orientation, a lower U value window glazing, higher insulation wall types, or a HVAC system with higher SEER value for example (Figure 313). Figure 312. Set up project location in GBS. (Source: Rundell 2008). The service uses precise hourly weather data, as well as historical rain data, that are accurate to within 9 miles of a given building site. It also uses emission data for electric power plants across the United States and includes the broad range of variables needed to assess carbon neutrality. Usually within minutes (depending on the model size and volume of information) the service calculates a buildings carbon emissions and the user is able to view the

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55 output in a web browser, including the estimated energy and cost summaries as well as the buildings carbon neutral potential. Users can then explore design alternatives by updating the settings used by the service and rerunning the analysis, and/or by revising the building model it self in the Revit based application and then rerunning the analysis. Figure 313. Design alternative configuration in GBS. (Source: Rundell 2008). LEED Water Analysis Using GBS Green Building Studio also summarizes the water usage (indoor and outdoor) and costs based on the project location, building occupancy type and fixture selection. LEED project teams will find the water calculation in GBS valuable since it is catered to address the requirements of the LEED Water Efficiency category (Figure 314). With a simple click, the project team could tell how many points the project could potentially achieve. Then with the computing table, designers can alter the fixture types by efficiency, and find the optimal strategy to achieve the desired LEED points (Fi gure 315).

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56 For really ambitious project teams, GBS also suggests measures to achieve net zero potable water usage through rainwater harvesting, graywater reclamation, and xeriscaping (using indigenous plants to eliminate supplemental landscaping irrigati on). The associated cost savings of net zero measures will also be estimated (Figure 316). Figure 314. LEED water credit calculation in GBS. Figure 315. Configure plumbing fixture efficiency in GBS.

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57 Figure 316. Achieve net zero potable water in landscaping. LEED Daylighting and View Analysis Daylighting and view is important to green building. Americans spend on average 90% of their time indoors. The well being and productivity of occupants can be improved by providing views to the exterior and by providing daylighting (USGBC 2007). A welldesigned daylit building is estimated to reduce lighting energy use by 50 to 80% (Public Technology Inc 1996). Daylighting design involves a careful balance of heat gain and loss, glare control, visual quality and variation in daylight availability. Shading devices, lighting shelves, courtyards, atriums and window glazing are all strategies employed in dayl ighting design. Important consideration include the selected buildings orientation, window size and spacing, glass selection, reflectance of interior finishes and locations of interior walls. Both IES (Figure 3 17) and GBS (Figure 318) can conduct c omprehensive daylighting and view simulation, with direct input of building orientation, geometry data, openings, shading device, glazing ratio, types and reflectance from the building information model. The process again is facilitated by the use of gbX ML as the interpreter between the model information and the analysis engine. The resul ts of these simulation are already made compatible with the LEED requirements, thus can be included by the project team in the submittals to GBCI for credit review.

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58 F igure 317. LEED daylighting assessment module in IES. (Source: Haynes 2008). Figure 318. LEED daylighting analysis in GBS. (Source: GBS 2009). BIM for Sustainability: Academic Research In parallel with the technology advancement in the industry, academia has made progress in quite diverse areas with investigating the potential of BIMs implementation in building sustainability. Laine and Karola (2007) identified that the main barrier preventing wider usage of dynamic energy analysis had been the l arge amount of work required to manually input data. They commented that by utilizing BIM as a data source for energy analysis, the data input would be more efficient and the existing data more reusable. They noted that only by using BIM, the verification of thermal performance could truly happen in different

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59 phases of the building process. They described a new concept and interoperable software environment for management of thermal performance during the whole building life cycle. Schlueter and Thesseling (2008) proposed a prototypical tool integrated into BIM software, enabling instantaneous energy and exergy calculations and the graphical visualization of the resulting performance indices, resulting in a higher flexibility of measures to optimize a build ing design. Huang et al. (2008) critiqued the defects of current simulation tools in terms of lack of interoperable tools and the difficulty in assessing tacit expert knowledge across building disciplines. They proposed a new scalable lighting simulation tool developed with the objective of reducing the time and effort required to use lighting simulation tools in integrated concurrent design. The simulation tool was based on the automatic creation of lightweight specific Domain Object Models (DOM) suitabl e for use by lighting simulation. The seamless sharing and reuse of building information between the design tool (Revit), the energy tool (EnergyPlus via Green Building Studio) and the new lighting simulation was thus achieved. Gillard et al. (2008) discus sed and illustrated how the use of BIM could be an essential tool for the design and maintenance of buildings, which were to be refurbished following a sustainable methodology. It was based upon a case study that explored how a small design practice, using ArchiCAD 3D BIM interchangeably with Ecotect building performance analysis software, could thus compete with major design practices in providing a superior service to clients, by demonstrating that the regeneration of a group of existing buildings is both more cost effective and more sustainable than new build.

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60 Integration Framework Development The efforts to integrate building information modeling and sustainability in the AEC industry come into two major forms: spontaneous integration and systematic integration. Previous paragraphs have been focusing on the spontaneous efforts that come directly from empirical evidence in the field and research on the specific technology application in a particular building system. However, it is critical to investi gate the full potential of this integration by taking a holistic view for the following reasons: Spontaneous efforts tend to be fragmented and case dependent. The success may or may not be documented and archived. The knowledge often is kept to the project only and thus cannot be referenced by future projects. Besides, building projects vary from one to the other significantly; experience learned in one project may not be applicable to other projects at all. Thus the benefits of empirical experience are usually limited to demonstrating the possibility instead of suggesting standard practice that could be replicated by the industry; and Research on a particular building system is meaningful only to the extent that how much impact the system generates on the w hole building. In contrast, a whole building approach provides the strategies to achieve a true highperformance building: one that is cost effective over its entire life cycle, safe, secure, accessible, flexible, aesthetic, productive, and sustainable. Through a systematic analysis of these interdependencies, and leveraging whole building design strategies to achieve multiple benefits, a much more efficient and cost effective building can be produced (WBDG 2010). A holistic integration of BIM and sustai nability will be at the framework level. The key elements of this integration framework include: interoperability facilitated by IFC and XML ; the internalization of sustainability within BIM ; and the use of a code checking approach to perform sustainabilit y compliance analysis. Interoperability Information and exchange constitute the essence and key activities of BIM (Figure 3 19). Fragmentation of the AEC industry is compounded by the diverse BIM solution

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61 market. It is not unusual that stakeholders engage d in the same project use distinct software solutions, especially when their roles require unique features of specific application. It is unrealistic to mandate that a completely interoperable package of BIM solutions should be adopted across the project i n that the project team is only a temporary collection of different stakeholders, starting when the project kicks off and ending at the moment when the project is accomplished. Transient partnership in the AEC industry to some extent eliminates the possibi lity to achieve a singlesourced, unilateral software solution for all companies in the industry. The direct impact of this heterogeneous environment for a building project is the loss of productivity. This is analogous to the project team members speaking different languages without an interpreter. Consequently, communication is severely handicapped, critical project information and data fail to be accurately disseminated. Figure 319. Facility lifecycle helix. (Source: NBIMS Committee 2007).

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62 Interoperability responds to the need to share data between applications, allowing multiple types of experts and applications to contribute to the work at hand via a specially contemplated format. Major exchange formats for interoperability now are typical ly carried out using one of the following four main approaches (Eastman 2008): Direct, proprietary links between specific BIM tools; Proprietary file exchange formats, primarily dealing with geometry; Public product data model exchange formats (IFC and CIS /2); and XML based exchange formats IFC and CIS/2 are the only public and internationally recognized standards today. Due to the limitation of CIS/2 to steel fabrication, the IFC data model is likely to become the international standard for data exchange and integration of the building construction industries. On the other hand, XML allows definition of the structure (often called schema) and meaning of the data of interest. The different schemas support exchange of many types of data between applications and they are especially good in exchanging small amounts of business data between two applications set up for such purpose. IFC and its support for sustainability Industry Foundation Class (IFC) is an ISO standard (ISO/PAS 16739) for exchange of constructi on data. The development, maintenance, and use of IFC and IFC enabled products are part of the buildingSMART initiative of the International Alliance for Interoperability (IAI). The term buildingSMART means integrated project working and valuebased lif e cycle management using BIM and IFC (STAND INN 2007). The purpose of IFC within buildingSMART is to enable interoperability between AEC software applications. The AEC industry is, by its nature, fragmented and distributed. It also encompasses a very lar ge set of interoperability requirements. Many axes could be described along which those requirements occur and can alter, such as:

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63 Disciplines involved in AEC/FM processes; Life cycle stages of AEC/FM projects; and Software application types used. To sati sfy all requirements the IFC Schema has to be structured in order to allow diversification to cope with the various information axes, as well as centralization to harmonize and integrate the various diversified modules. Therefore the IFC Schema was set up: As a single integrated schema to enable cross discipline, life cycle and level of detail exchange; and Using a modular architecture to facilitate the specialization of discipline and life cycle specific modules within the integrated IFC Schema. In IFC each object is traceable with its own birth number, the GUID (Global Unique ID). The vision behind the buildingSMART is to enable efficient information flow during the complete lifecycle of the building. IFC compliant building information models form part of the foundation to this vision (Kiviniemi et al. 2008). In general, to be able to share information, three specifications must be in place (Bell and Bjrkhaug 2006): An exchange format defining HOW to share the information. IFC is such a specification; A reference library defining WHAT information we are sharing. The IFD Library (an implementation of ISO 120063) serves this purpose; and Information requirements defining WHICH information to share WHEN. The IDM/MVD approach forms that specification. IFC was developed as an extensible framework model to provide broad general definitions of objects and data from which more detailed and task specific models supporting particular workflow exchanges can be defined. It was designed to address all building i nformation (implies the inclusion of building performance and sustainability information), over the whole building lifecycle, from feasibility and planning, through

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64 design (including analysis and simulation), construction, to occupancy and operation (Kheml ani 2004). As of 2008, the current release of the IFC is Version 2x4 beta 3. Figure 320 shows the system architecture of IFC subschemas. IFC is not the data per se but an exchange format that could facilitate data exchange between different software applications In regard to sustainability, pertinent research is currently conducted by the European research group EUROPE INNOVA ( http://www.europeinnova.eu/web/guest/home), with their noticeable STANDINN series of reports on IFC support for sustainability integration in buildings. Figure 320. Architecture diagram of IFC 2x4 Beta 3. (Source: IAI 2009).

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65 The STAND INN (2007) report series covered a wide range of investigation on IFC support for sustainability, including Deliverable 13: IFC Support for Sustainability; Deliverable 15: IFC and IFD Feasibility for Innovative Sustainable Housing; and Deliverable 16: Guidance on IFC/IFD for Innovative Sustainable Housing. The impacts of the STAND INN research were far reaching. As for IFC/BIM and sustainability, the deliverables of this research are: Established a life cycle based sustainable construction roadmap using building information models (Figure 321); and Identified the IFC/BIM supported sust ainability indicators/applications (Table 34). Figure 321. IFC/BIM supported sustainable construction. (Source: Haagenrud 2007). Table 34. IFC/BIM supported sustainability applications (Source: Haagenrud 2007) Sustainability Applications Support Level (increase by number of Life Cycle Assessment (LCA) Environmental Product Declaration (EPD) Life Cycle Costing (LCC) Energy Performance Declaration Environmental Impact Adaptability to change in use Reusability/Recycling Service life planning Social Impact Energy efficiency

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66 XML and its support for sustainability Extensible Markup Language (XML) has become very popular for information exchange between Web applications, e.g. to support ecommerce transactions and customer data collection. An XML schema is a description of a type of XML document, typically expressed in terms of constraints on the structure and content of documents of that type, above and beyond the basic syntactical constraints imposed by XML itself. The schema determines what data and how the data will be stored and presented. Current XML schemas in AEC industry include but are not limited to: The aecXML is an XMLbased language used to represent information in the Architecture, Engineering and Construction (AEC) industry. This information may be resources such as projects, documents, materials, parts, organizations, professionals, or activities such as proposals, design, estimating, scheduling and construction. It is intended to be used as an XML namespace and to facilitate information exchange of AEC data on the Internet ( www.aecxml.org ); The agcXML p roject, inaugurated and funded by The Associated General Contr actors of America (AGC), resulted in a set of XML schemas for the transactional data that is now commonly exchanged in paper documents such as owner/contractor agreements, schedules of values, requests for information (RFIs), requests for proposals (RFPs), architect/engineer supplemental instructions, change orders, change directives, submittals, applications for payment, and addenda, to name a few. The agcXML Project is being executed as part of the aecXML domain framework under the auspices of buildingSMA RT alliance ( www.agcxml.org ); The gbXML (Green Building XML) has been discussed in previous paragraphs in the energy simulation part. The gbXML open schema helps facilitate the transfer of building properties stored in 3D building information models to engineering analysis tools. Today, gbXML has the industry support of leading 3D BIM vendors such as Autodesk, Bentley, and Graphisoft. In addition, with the development of integration modules inside major engineering analys is tools, gbXML has become the defacto industry standard schema. Its use dramatically streamlines the transfer of building information to and from engineering analysis tools, eliminating the need for time consuming plan takeoffs. This removes a significant cost barrier to designing resource efficient buildings and specifying associated equipment ( www.gbxml.org ); and The ifcXML representation is an implementation of the ISO 10303 Part 28 Edition 2 standard. This standard provides an XML schema specification that is an automatic conversion from the EXPRESS (ISO 10303 part 1) representation of the IFC

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67 schema. The mapping from EXPRESS to XML schema is guided by a configuration file that controls the specifics of the translation process. For ifcXML this configuration file is standardized and published for each version of the corresponding IFC schema (Nisbet and Liebich 2007). The advantages of using XML as the information exchange format were summarized by Liebich (2002) as: XML was commonly used and relevant XML knowledge was widely available in companies and organizations; Variety of development tools were cheaply availabl e; and XML was easy to integrate with browser and other standard software. Internalize Sustainability within BIM Perceiving the broad pursuit of green building in the industry and the popularity of BIM technology, some scholars have been working on strategies to internalize the sustainability within BIM. This entailed the creation of a customized sustainable design criteria embedded in the existing BIM authoring tools. Ideally, the designers would have access to prescribed sustainability requirements from t he inception of the building design. An immediate practical set of sustainability criteria is easily found in a green building rating system. Biswas et al. (2008) briefly illustrated how a sustainable building rating system could be adopted into a building information model to offer designers an environment to work with an enhanced integrated awareness of different sustainability factors. A general framework of sustainable measures was proposed to encompass the categories and subcategories of commonly used rating systems. A prototype sustainable building information model (SBIM) application was proposed to aid designers in keeping in mind the different design aspects that they needed from the early design phases.

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68 Barnes and CastroLacouture (2009) described a BIM enabled integrated optimization tool for LEED decisions. The optimization tool would assist project stakeholders in the selection of material, equipment and systems at every stage of the construction project life cycle, considering the best value w ith regard to the applicable green building rating system score, e.g. the LEED system. Using BIM in this approach, Barnes and CastroLacouture argued, would allow owners, designers and contractors to choose the item on the spot from a 4D representation. Thus the decisions could be made in a timely fashion and with effective communication to cut down on additional costs that were inevitable in largescale construction projects. Code Checking: Sustainability Compliance The idea of using BIM technology to check projects compliance with building codes was first adopted in Singapore. The Construction and Real Estate Network (CORENET) initiative was launched in 1995 and its aim was to reengineer and streamline the fragmented work process in the construction industry, so as to achieve quantum improvements in turnaround time, quality and productivity. To drive the seamless exchange, management, comprehension and integration of project information or interoperability across diverse platforms, the adoption of building information modeling was identified as a critical cornerstone (Teo and Cheng 2005). The Building and Construction Authority of Singapore approved the implementation of the CORENET ePlan Check System in 2004 (Figure 322). As illustrated, the three kernel modules in automatic code checking included: the ePlan Check System, the Rules Schema (computer parsed building codes) and the IFC building information model (created by a BIM authoring tool). With this ePlan Check System, building professionals (such as registered architects and professional

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69 engineers) could prepare their design using object oriented BIM tools and then upload the BIM into ePlan Check System for automatic online or batch processing. When the automatic checking process was completed, the system would generate a downloadable report to highlight the areas of noncompliance. Figure 322. CORENET e Plan Check System. (Source: Teo and Cheng 2005). The conventional code checking and approval process using the manual approach was labori ous and inefficient. With the ePlan Check System, the checking process was significantly speeded up. With careful rule schema design, the ambiguities and subjectivity were also reduced in the building code interpretation and regulatory compliances. New tr ends in the code checking research now include the engagement of construction safety and building sustainability. With a special interpreter, safety regulations such as the Occupational Safety and Health Administration (OSHA) standard in the U.S. could be written in the computer readable format similar to the new

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70 Rules Schema module in the ePlan Check System. The same logic may apply to the sustainability except for the fact that sustainability or green building practice has not yet been written into build ing codes in any country around the world. However, the possibility is open, and some voluntary based initiatives have been working on the piloting efforts to realize quasi codechecking system for buildings compliance with sustainability. The International Code Council (ICC) and their SMARTCodes project is a noteworthy example. By collaborating with leading model checking software companies such as Solibri and AEC3, ICC set out to automate code compliance checking in the AEC industry. The SMARTCodes project is critical since it defines the machineinterpretable Rules Schema that contains the business rules to be checked against in the code checking process. Currently the most comprehensive SMARTCodes is the International Energy Conservation Codes (IECC). Meanwhile, the International Green Construction Code (IGCC) was published in March 2010 (ICC 2010). IGCC is conceived as a model code focused on new and existing commercial buildings addressing green building design and performance. The IGCCs unique draft ing approach links the International Codes to a public process bringing together diverse areas of expertise to create the first integrated, regulatory framework for green commercial buildings. The codechecking approach to integrate sustainability into BIM is unique and may bring fundamental changes to current practice.

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71 CHAPTER 4 METHODOLOGY Overview This chapter presents the methodology of this research. A phaseby phase roadmap is implemented in this research: 1) Starting with a proof of concept survey, this research firstly looks into the actual needs, gaps and expectations in the industry regarding why and how applicabl e the integration of BIM and LEED rating system and certification is. 2) A generic integration framework is established to create the theoretic foundation for the BIM LEED application model. Then a gap analysis is performed to find out what desirable functionalities are missing in current BIM solutions, especially in the Revit suite and supplemental software applications. 3) The BIM LEED application model (or Revit LEED application model in this particular software environment ) consists of two modules: the LEED oriented design assistance module and the LEED certification management module. 4) To verify the application model, a use c ase of the LEED Materials and Resources category is created. Figure 41 illustrates the logic of the research workflow. Figure 41. R esearch workflow.

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72 Feasibility Survey It is believed that the following pair of questions is critical to developing the i ntegration framework: What does the LEED rating system and certification require? What solution can BIM provide? Put another way, the first step to the generic integration framework should provide the answer to the following question: How do we match up t he functionalities of BIM with the LEED certification requirements? The integration process has been handicapped due to the fact that so far no consensus has been reached as to how applicable and to what extent this integration can be. The survey was thus conducted to collect AEC professionals opinions about how feasible it is in technology and operation terms to integrate BIM and LEED when breaking LEED down to the credit level along with the project delivery process. This survey also aims to find out what expectations and recommendations professionals have on this integration to make it more than a concept, a functioning mechanism. The results of this survey can then be used as a guideline for more indepth development of the integration model. The feasibility survey is designed for professionals in the AEC industry with different levels of involvement in BIM and LEED. It includes two major parts and a supplemental comment part. PART 1 asks four general demographic questions of the participants, and assess es their knowledge about BIM and LEED. Section 1 of PART 2 lists ten statements soliciting the participants perception of the current BIM software tools in regard to their impacts on the LEED certification process in terms of cost, time, documentation, pr oductivity and other typical issues in the project delivery. Section 2 of PART 2 addresses the structure of the LEED NC 2009 rating system to investigate

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73 participants opinions about the applicability of BIM LEED integration at a credit by credit level. A complete survey questionnaire is attached in Appendix A. Generic Integration Framework The generic integration framework is established on the matchup of the LEED credit requirements and the functionalities available from current BIM solutions, for the purposes of this research, the Autodesk Revit software suite and supplemental software application from Autodesk. Two major tasks in establishing the framework include: Evaluating LEED credits requirements: Credits in the LEED rating system are organized in a consistent manner. Generally speaking, every credit has an accompanying explanation describing what issue that credit is trying to address; and the requirements elaborate the details that the project team should follow to be eligible for the applying for the corresponding LEED points. Credit requirements are descriptive and spell out the qualitative information that the project team should provide. More likely, the requirements specify the quantitative t hreshold of certain metrics that request for data. Since a major goal of the LEED rating system is to benchmark the building performance, the comparison conducted between the green building and the conventional building is inevitable. In this case, the project team should carefully interpret these requirements into the required data, and collect such data during the design and construction process; and Screening available functionalities of Revit and supplemental BIM solutions: The functionality inventory of these software applications may or may not be sufficient to satisfy the LEED credits requirement. For those credits with immediate available functionalities, a mark up will be performed to lock the relationship between the requirements and the functional ity. For credits that have complex data requirements, some joint functionality across different software may resolve the problem. However, it is possible that no existing functionality can meet the requirements of certain credits. In this case, a gap is identified to be evaluated later for possible solution. In addition to the contents of the LEED rating system, the certification process involves extra commitment to administrative issues. Since LEED is a point system, the number of points the project can possibly achieve will directly determine the certification outcome. Thus it becomes important for the project team to monitor the status of the points balance. Ideally, this is done right at the inception of the project planning stage.

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74 With the owners expec tation clearly spelled out, the project team will be able to work with the owner to go through the LEED checklist and find a strategy for what level of certification to look at; which credits and how many points to pursue from a cost benefit perspective; w hat the essential design and construction challenges faced by the project are; and what the proposed solutions are. This strategy is often called the LEED Strategy and the process is known as the Design Charette The proposed integration framework should take the administrative aspects into account to provide the project team control over the LEED point status along with the project delivery. BIM LEED Application Model The BIM LEED application model operates on top of the integration framework. Once the owner decides to pursue the LEED certification, this application model is triggered. With the work done in the integration framework part, the application model will immediately obtain the data requests from the requirements for each credit. All t he credits whose requirements can be met with existing functionalities will go through the necessary internal operation in the BIM solution for direct data feedback, then proceed to the preparation of relevant documentation and submittal, and eventually be ready for submission to USGBC through LEED Online (Figure 42). For the credits without support of immediate functionalities, two approaches are proposed to tackle the identified gaps: External information from other incompatible applications may still contribute data through the intermediation of IFC and XML; and New functionalities may have to be developed through the Revit API provided by Autodesk.

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75 LEED Credit Requirements Analysis Mapping Revit Functionality Interpret into Data Input Request Internal Functionality Available Direct Data Extraction Feedback Yes Request for External Functionality No New Functionality No Revit-API Extension Development Yes IFC or ifcXML Intermediation Yes Exchanged Data Feedback Newly Extracted Data Feedback Interoperability All MPR and LEED Prerequisites Satisfied Yes No Documentation and Submittal Prepartion Project Team Committed to LEED Certification Application Model Triggered Out of Research Scope: Process Terminated Certification Abandon: Process Terminated No Yes LEED Points Achieved Adequate Points for Target LEED Certification Level LEED Certification Achieved. Project Goal Accomplished Yes Yes No No No Figure 42. The logic flow of the BIM LEED application model. In regard to the contents of the BIM LEED application model, it consists of two major modules: The LEED oriented design assistance module: In order to extract data for the LEED certification purpose, the building information model in the first place should be created in a LEED oriented manner. It is not unusual that the architects and engineers in a project are new to the LEED rating system. Even for accredited LEED professionals, the contents and details of the rating system are still overwhelming. To accommodat e these subtleties, the application model provides designers real time assistance in LEED information to ensure that the outcome building information model will cater to the certification needs.

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76 The LEED certification management module: The need to provi de the project team especially the contractors a more efficient documentation management system is recognized. As previously discussed, documentation quality is the key to the success of the certification. A webbased certification management application built on the Apache/MySQL/PHP is then proposed to streamline the documentation generation, management and submission during the LEED project delivery. This module acts like a LEED specific project management system with emphasis on information and documentation. LEED Materials and Resources Use Case The LEED Materials & Resources use case is created to verify the integration framework and preliminarily validate the BIM LEED application model. All credits (including prerequisites) in the Materials and Reso urces category will be analyzed and interpreted into data requests. The functionalities will be mapped against these requests and gaps will also be identified. The use case simulat es the real LEED project delivery process. By implementing the application m odel step by step, the requirements to achieve the MR credits are fulfilled, the documentation to show such compliance and the submittals sent to GBCI for review are generated. Sample plugins are programmed into Revit to provide design assistance, and a prototype of the web based LEED certification management application is developed.

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77 CHAPTER 5 RESULTS AND DISCUSSI ONS Results: Feasibility Survey The survey was deployed using the Zoomerang web based survey tool ( http://www.zoomerang.com ). The survey was active from June 30th, 2009 to August 1st, 2009 posted at LinkedIn ( http://www.linkedin.com a business oriented social networking website ) to professional groups including BIM Architecture, BIM Expert, BIM and the AEC Profession, BuildingSMART, Club Revit, Collaborative BIM Advocates Green Revit API, Group for Building Information Modeling and Revit Users These professionals represented a large number of active stakeholders in the BIM arena who routinely used the web as a means for information exchange and knowledge sharing. They had experience and felt comfortable with webbased research activities. Similar surveys have previously been con ducted in LinkedIn among these same groups. A total of 190 people accessed the survey, 64 finished it partially and 35 (18% response rate) completed the questionnaire (some might have missed 1 or 2 questions). The results of the survey were then imported into a statistical software package (SPSS 17) for analysis. P art 1: General Information The participants in this study had the following backgrounds. Arc hitects/Engineers constituted the greatest portion (20 out of 35), followed by general contractors (7 out of 35), owners (3 out of 35) and no (0) subcontractors responded (See Figure 5 1). The Other category (5 out of 35) included majorly c onsulting companies and BIM software vendors. The absence of subcontractors might be as meaningful as the dominance of the Architects/Engineers in the respondent group. Historically A/E companies are more

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78 resilient to technology transition due to their dir ect involvement in such transition, and often times they are the market drivers. Conversely, subcontractors are at a lower tier of the industry supply chain, and they are quite passive and tend to lag in adoption of innovative technologies. Lack of budget or fear of risks in using new technologies might also account for their reluctance to commit to BIM. Figure 5 1. Companys role in a construction project Based on the definition of BIM from the NBIMS Committee (2007), 14 (40%) of the participants declared that they had previously participated in projects fully adopting BIM, while another 14 (40%) indicated that they had worked on projects that partially used BIM (see Figure 5 2). Only 2 (5.7%) admitted they had limited knowledge about BIM and knew the c oncepts only. The high BIM adoption rate by architects and engineers could be explained again in relation to the fact that architects and engineers were

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79 dominant in this survey, and they are earlier adopters of BIM according to McGraw Hill Construction (2008). Figure 5 2. Companys experience with BIM There are various software applications of BIM in todays market. Despite the advantages and disadvantages of each of these varied applications, the Autodesk Revit software suite (including Revit Architecture, Structure and MEP) is arguably the most popular BIM software tools in the U nited S tates The 74.3% usage rate of Revit in this study corresponded to the findings of the McGraw Hills SmartMarket Report in 2008, which reported a 67% Revit adoption rate. Bentley System, ArchiCAD and Vico also had a certain market share ( Figure 5 3). In the Other category, participants also indicated use of tools such as DProfiler, Digital Project, Onuma Planning System, Navisworks to name a few. The fact that lots of companies used more than one software application created concerns about interoperability issues due to the information exchange demands among software packages. As for LEED, chances are 2 6% 1 3% 3 8% 14 40% 14 40% 1 3% Understand the concept only Have purchased BIM authoring tools and started employee training Have participated in projects using BIM as reference only Have participated in projects partially adopting BIM Have participated in projects fully adopting BIM (Plan, Design, Construction, O&M) Other

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80 that not a single application can adequately tackle the compl exity and magnitude of the issues encountered in the project delivery. Thus, it is inevitable to deal with the problems created by the use of different software applications. The prevalence of Revit has had an impact on the market since most peripheral sof tware providers have preferred to develop plugins and addons compatible with the Revit platform, which will eventually contribute to the centralization of BIM solutions. Figure 53. BIM authoring tools used by the respondents (select all that apply). For questions with multiple answers, the percentage is calculated by dividing the frequency by the total number of completed questionnaires (35). When asked about their experience with the LEED rating system, as many as 26 out of 35 (74.3%) respondents indicated that they had previously worked on projects that successfully achieved the LEED NC certification. A few of them (5 out 35, 14.3%) indicated that they had limited knowledge about LEED (See Figure 5 4). It seems from the survey results that the green building market has become quite mature in the United 26 5 5 3 3 10 74.30% 14.30% 14.30% 8.60% 8.60% 28.60% 0 5 10 15 20 25 30 Revit Suite Bentley System ArchiCAD Vico Software Vectorworks Other

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81 Sates. The AEC professionals who had substantial understanding of the LEED rating system and who were practicing BIM, tended to be more inclined to leverage LEED project delivery with BIM. Figure 54 Respondents companys experience with LEED NC (all LEEDNC versions may apply). Considering that most completed or ongoing LEED NC projects are prior to LEED NC 2009, it is reasonable to include all versions here. Part 2 Section 1: Perception on Status Quo Assumptions on how BIM would help sustainability and LEED certification vary from case to case. Lots of promises have been made without adequate justification. Essentially, it is not yet clear where the AEC industry is currently at in terms of realizing these promises. Lots of companies have been exposed to stateof art BIM practice from case studies (e.g. Krygiel and Nies 2008) and marketing brochures distributed by software companies. But they do not have access to solid data that they can rev iew and learn from so as to replicate the success in their own business operations. 5 14% 2 6% 26 74% 2 6% Understand the concept only Have in house LEED APs but no actual LEED NC project experience Have participated in projects that pursued LEEDNC certification and succeeded Other

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82 Consequently, a benchmark of the status quo in BIM integration with sustainability and LEED becomes valuable to help companies pinpoint their positions in a competitive mar ket. Section 1 of PART 2 in the survey used ten questions to solicit the perception of current implementation of BIM in LEED certification (majorly in the LEED NC v2.2 certification). Each question was assessed using a 7point Likert scale representing sev en levels of perceptions ranging in value from 1 for strongly disagree with an increment of 1 to 7 for strongly agree (see Appendix A). It should also be noted that not all 35 participants completed all questions in this section, so the value of N was given in Figures 5 5 to 5 1 4 to indicate the number of valid answers that were actually attained. Figure 55 C urrent BIM solutions are adequate for LEEDNC v2.2 project delivery.

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83 Figure 56 Full integration of BIM in LEED NC v2.2 project del ivery is realized Figure 57 BIM is effective in the preconstruction stage of LEED NC v2.2 projects.

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84 Figure 58 BIM is effective in the construction stage of LEED NC v2.2 projects. Figure 59 C urrent BIM tools can help formulate LEED s trategies

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85 Figure 510 C urrent BIM tools can facilitate the generation and dissemination of design and contract documents. Figure 511 C urrent BIM tools can facilitate communication and information exchange between project members.

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86 Figure 512 C urrent BIM tools can facilitate certification documentation generation and submission to LEEDOnline Figure 513 Current BIM tools can help reduce upfront cost of pursuing LEED NC v2.2 certification.

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87 Figure 51 4 Current BIM tools can increase t he overall chances of achieving LEED NC v2.2 certification. As shown in Figure 55, the respondents somewhat disagreed, with a mean score of 3.53, with the sufficiency of current BIM software tools in meeting the LEED NC v2.2 requirements. Figure 5 6, with a mean score of 3.21, shows that respondents did not think their companies had fully integrated BIM solutions into LEED project delivery. Figure 57 shows that they acknowledged the benefits of using BIM at the preconstruction stage in a LEED project (mean score of 4.29). However, a mean score of 3.88 (see Figure 58) reveals the participants doubts about the role of BIM in the construction stage. On the other hand, they were very convinced (mean score> 5.00) about utilizing BIM for their LEED strategy (Figure 59) (for instance, review which LEED points w ere perceived more feasible than others); generating and disseminating better quality contract documentation (Figure 510); creating submittals as required by

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88 LEED certification (Figure 512); and improvi ng communication and collaboration between project teams (Figure 511). With an average score of 4.82 (see Figure 513) the respondents tended to agree that with the assistance of BIM, they could potentially reduce the upfront cost involved in obtaining LE ED certification. They were also optimistic (mean score of 4.76) that with the facilitation of BIM the project might have a better chance to get LEED certified (see Figure 514). To summarize this part of the survey, companies should be aware of their uni que roles in the AEC industry so as to customize their strategy for BIM implementation in their own business operation. A fundamental goal should be set so as to maximize the benefits derived from the use of BIM applications while simultaneously being caut ious to avoid the potential loss attributed to inefficiencies inherent in current BIM technologies. For instance, it is worthwhile for contractors to identify the factors that have diluted the synergies between BIM and LEED at the construction stage, and w hat action they could take to fix them and generate more benefits from BIM adoption. Part 2 Section 2: Feasibility Analysis The result from Part 2 Section 1 was helpful in identifying issues that needed to be addressed in the long term to make BIM LEED integration successful. But for the project teams they were more concerned about whether there were sound solutions to the immediate problems that they came across in the project in regard to the details of the LEED credits. The next set of questions, Part 2 Section 2 of this survey, addressed the issue of how feasible it is to use these BIM solutions to score those LEED points. Credits for all seven categories in the LEED NC 2009 rating system were assigned a numeric value (0 as not applicable whi le 5 meant most applicable) to indicate the level of applicability when incorporating current BIM solutions to help

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89 pursue the corresponding LEED points (see Appendix A). Participants were asked to determine the value based on their experience, knowledge or assumption. In Category 1 Sustainable Sites, Credit 8: Light Pollution Reduction credit (SSc8) received the highest mean score of 3.34, while Credit 4: Alternative Transportation (SSc4) received the lowest mean score (1.94). Participants commented that an embedded linkage with GIS in BIM could significantly help the attainment of points in this category. Site vicinity information such as proximity to public transportation, community connectivity, and infrastructure can be easily extracted from local or national GIS sources to help the project team make better informed decisions. Table 51 summarizes the scores for Category 1 Sustainable Sites. Table 51 Applicability levels in Category 1 Sustainable Sites SSp1 SSc1 SSc2 SSc3 SSc4 SSc5 SSc6 SSc7 SSc8 N* Valid 32 32 32 32 31 32 32 31 32 Missing 3 3 3 3 4 3 3 4 3 Mean 2.31 2.72 2.69 2.09 1.94 2.88 2.94 3.19 3.34 Std. Deviation 1.575 1.550 1.424 1.376 1.315 1.385 1.190 1.424 1.599 *N = number of responses. In Category 2 Water Efficiency, the scores were relatively stable for each credit. Comments from participants suggested that the use of BIM would not necessarily be advantageous over conventional 2D applications such as CAD in terms of improving the perf ormance of water efficiency Also there were complaints about the complexity of using current BIM software tools for mechanical, electrical and plumbing (MEP) systems in general. Table 52 summarizes applicability levels in this category. In Category 3 E nergy and Atmosphere, best consensus was achieved on the energy performance related credits, Minimum Energy Performance (EAp2, mean score at 3.78) and Optimize Energy Performance (EAc1, mean score at 3.78). Building energy

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90 performance had been at the heart of building modeling and simulation research. T he capabilities of BIM technologies were enhanced by incorporati ng geographical and weather data into design c onsideration to optimize the orientation, massing, day lighting, and natural ventilation, to name a few It wa s worth noting that there wa s an inconsistency between the Fundamental Commissioning of Building Energy Systems (EAp1) with mean score of 3.16 and Enhanced Commissioning (EAc 3 ) with a mean score of 2.59. Building commissioning play s a significan t role in ensuring that the completed facility has actually met the design performance and w ill maintain such performance throughout the buildings life cycle. Table 53 summarizes the responses in this category. Table 52 Applicability levels in Category 2 Water Efficiency WEp1 WEc1 WEc2 WEc3 N Valid 32 32 32 32 Missing 3 3 3 3 Mean 2.78 2.44 2.47 2.72 Std. Deviation 1.211 1.190 1.436 1.224 Table 53 Applicability levels in Category 3 Energy and Atmosphere EAp1 EAp2 EAp3 EAc1 EAc2 EAc3 EAc4 EAc5 EAc6 N Valid 32 32 32 32 32 32 32 32 32 Missing 3 3 3 3 3 3 3 3 3 Mean 3.16 3.78 2.31 3.78 3.09 2.59 2.44 3.19 2.59 Std. Deviation 1.668 1.289 1.615 1.313 1.445 1.682 1.458 1.575 1.316 In Category 4 Materials and Resources, most scores fell between 2 and 3 except for Building Reuse (MRc1) with a mean score of 3. 4 4. Submittals for MRc1 require d calculation of the reused area of structural building components such as walls, floors and the roof, which could be easily obtained from the BIM model. The key to better applicability of BIM in this category as suggested wa s to creat e an imbedded material library customized for an integrated BIM LEED work environment. For instance, quite a

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91 few participants mentioned they would be more willing to pursue MRc4: Recycled Content if an industrial directory that listed local recycled/salvaged material suppliers by zip code was internalized in the database of current BIM software tools. Additionally, some of the respondents again brought up making GIS linkage a built in function in the building information model in order to streamline the analysis of credits such as MRc5: Regional Materials. Table 5 4 summarizes responses in this category. Table 54 Applicability levels in Category 4 Materials and Resources MRp1 MRc1 MRc2 MRc3 MRc4 MRc5 MRc6 MRc7 N Valid 32 32 32 32 32 32 32 32 Missing 3 3 3 3 3 3 3 3 Mean 2.66 3.44 2.16 2.97 2.84 2.41 2.50 2.53 Std. Deviation 1.035 1.294 1.322 1.092 1.370 1.341 1.344 1.391 In Category 5 Indoor Environmental Quality, participants had distinct opinion s on the applicability levels for different credits. IEQc8: Daylight and Views scored a mean of 4.13, while IEQp2: Environmental Tobacco Smoke Control had a mean score of 2.10. As previously discussed, weather data, solar intensity level and building orient ation c an be incorporated and configured easily in a building information model Design professionals g o t better control over the subtleties with the numerous options enabled by current BIM technology to achieve optimal daylighting strategy Visualization could be enhanced in a well constructed building information model with adequate site details. Clients could virtually see what the building w ould look like after construction, and make adjustments to their actual view needs in a real time manner Green Bu ilding Studio and IES were mentioned by respondents as popular tools in daylight and view design. Table 55 summarizes the responses in Category 5.

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92 Table 55 Applicability levels in Category 5 Indoor Environmental Quality IEQp 1 IEQp 2 IEQc 1 IEQc 2 IEQc 3 IEQc 4 IEQc 5 IEQc 6 IEQc 7 IEQc 8 N Valid 31 31 30 30 31 31 31 31 30 31 Missing 4 4 5 5 4 4 4 4 5 4 Mean 3.06 2.10 2.83 3.30 2.45 3.03 2.74 3.23 3.40 4.13 Std. Deviation 1.526 1.446 1.315 1.179 1.362 1.016 1.264 1.359 1.163 1.258 Category 6: Innovation in Design and Category 7: Regional Priority are quite descriptive in nature. The respondents suggested that the integration of BIM in LEED per se should be regarded as innovative and indicated that they would not mind using it as a m arketing tool for their projects. On the other hand, pursuit of points in LEED A ccredited P rofessional and identifying R egional P riorities did not necessarily involve the use of BIM. Table 56 summarizes both Category 6 and Category 7 responses Table 5 6 Applicability levels in Categories 6 and 7 IDc1 IDc2 RPc1 N Valid 31 30 31 Missing 4 5 4 Mean 3.68 1.83 2.32 Std. Deviation 1.641 1.802 1.469 Survey Summary T he investigation of user perceptions of the status quo preliminar ily benchmark ed current BIM solutions and their applicability in LEED projects. It revealed that in spite of acknowledging the great potential of BIM, professionals were apprehensive about its value at the actual construction stage of the LEED project delivery process. They recognized the opportunity to take advantage of BIM technology in pursuit of specific LEED points; nonetheless they indicated that they would not rely exclusively on BIM to compile LEED certification documentation. In addition, some comments from the p articipants were very constructive for future BIM software development. For instance,

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93 more than a few professionals suggested t he need for business directory to be built in the BIM authoring tools. This directory could list material suppliers and categorize their products with recycled contents, regional materials, or other LEED oriented information by zip code This w ould greatly promote designers selection of more environmental friendly products while also contribut ing to the LEED certification needs. A nother highly desirable feature mentioned by the respondents was the linkage to GIS data in the BIM authoring tools. GIS information can be particularly valuable to site selection and the connectivity of the building project to the local community. Results: Generic Integration Framework The principle to integrate BIM and LEED certification is straightforward. T he requirements of LEED credits should be matched up with the functionalities of BIM solutions. Figure 51 5 describes this intuitive relationship. Figure 51 5 Intuitive relationship of the i ntegration f ramework

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94 When going into the actual integration process, the LEED rating system is broken down into credits, and eventually the requirements clauses. Each statement of the requirements is either a descriptive request or a quantitative specification. For instance, MRp1 Storage and Collection of Recyclables requires: Provide an easily accessible dedicated area or areas for the collection and storage of materials for r ecycling for the entire building. Materials must include, at a minimum: paper, corrugated cardboard, glass, plastics and metals. ( USGBC 2007 ) This is a typical descriptive request. The key words in this request include easily accessible, dedicated area recycling, materials, paper, corrugated cardboard, glass, plastics and metals The descriptive request often involves only text type keywords. In contrast, MRc3 Material Reuse requires: Use salvaged, refurbished or reused materials, the sum of which constitutes at least 5% or 10%, based on cost, of the total value of materials on the project. (USGBC 2007) This is a typical quantitative request. The key words in this request include salvaged, refurbished, reused, materials, %, 10%, cost, and total value. The quantitative request should at least include one or more numeric type keywords. From the BIM functionality inventory perspective, those functionalities have to be dependent on the building information model or model components In other words, without the model, those functionalities cannot be checked out, thus they will not be able to be executed For instance, schedules is an important feature that captures comprehensive information (e.g. material property, geomet ry, count and cost) for a specific category (e.g. doors and windows) of the building information model. If the category was not presented in the model, then the schedule for that particular category will not be able to collect any information. Under certai n circumstances, a type of

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95 functionality is dependent on certain model components plus the relationship between these components. The relationship can be static (e.g. geometric) or dynamic (e.g. sequencing) The complexity of the matchup between the LEED requirements and the BIM functionalities is illustrated in Figure 51 6 Column A shows a group of indicator type measures embedded in the rating system while Column C shows the building information model broken down in to the component level in the popular CSI format. In Revit, every model object is assigned an assembly code defined by the Uniformat system. Accordingly, Column C in Figure 51 6 could be rearranged into Uniformat. Figure 51 6 Integration framework relationship developed (Source: adapted from Biswas et al. 2009). Interpret ing LEED Requirements The following paragraphs perform the analysis of all LEED credits and their requirements by category, mark up the key words, and interpret them into descriptive or quantitative data requests. Starting with LEED v3, the project has to satisfy the

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96 Minimum Program Requirements (MPRs) to be eligible for certification. The MPRs thus become part of the general requirements, and are included in the analysis. Minimum program requirements Table 57 Interpreting report of MPR 1 MPRs define the types of buildings that the LEED Green Building Rating Systems were designed to evaluate, and taken together serve three goals: to give clear guidance to customers ; to protect the integrity of the LEED program ; and to reduce complications that occur during the LEED certification process (GBCI 2009). MPR1 Must comply with environmental laws stipulates that t he LEED project building or space, all other real property within the LEED project boundary, and all project work must comply with applicable federal, state, and local buildingrelated environmental laws and regulations in place where the project is located. This condition must be satisfied from the date of LEED project registration or the commencement of schematic design, whichever comes first, up and until the date that the building receives a certificate of occupancy or similar official indication that it is fit and ready for use. Table 57 illustrates a typical report of the LEED requirement and an interpret ation of it The key words have been identif ied and summarized. This is a typical D escriptive request The most suitable data type is either a Yes or No Boolean type or T ext type. Due to the similarity of the rest of the MPRs, the detailed process of interpreting them will be skipped. The results are summarized in the ensuing T ables 5 7 to 5 13. Item Description LEED Category MPR 1 : Must Comply with Environmental Laws Key Words project building or space, real property, project boundary, project work, project registration, schematic design, certificate of occupancy Request Type Descriptive Proposed Data Type Yes or No; Text Proposed Submittal Checklist; LEED Online template; Attachments ;

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97 Table 5 8 Interpreting report of MPR 2 Item Description LEED Category MPR 2 : Must be a Complete Permanent Building or Space Key Words permanent location, existing land, commercial, institutional, or high rise residential, entirety Request Type Descriptive Proposed Data Type Yes or No; Text Proposed Submittal Checklist; LEED Online template; Attachments Table 5 9 Interpreting report of MPR 3 Item Description LEED Category MPR 3 : Must use a Reasonable Site Boundary Key Words all contiguous land, normal building operations, no gerrymandering Request Type Descriptive Proposed Data Type Yes or No; Text Proposed Submittal Checklist; LEED Online template; Attachments Table 5 1 0 Interpreting report of MPR 4 Item Description LEED Category MPR 4 : Must Comply with Minimum Floor Area Requirements Key Words minimum of 1,000 square feet, gross floor area Request Type Quantitative Proposed Data Type Numeric; Logic al Proposed Submittal Calculation ; LEED Online template Table 5 1 1 Interpreting report of MPR 5 Item Description: Must Comply with Minimum Occupancy Rates LEED Category MPR 5 Key Words 1 or more Full Time Equivalent occupants, annual average Request Type Quantitative Proposed Data Type Numeric; Logic al Proposed Submittal Calculation ; LEED Online template Table 5 1 2 Interpreting report of MPR 6 Item Description LEED Category MPR 6 : Must Commit to Shar ing Whole building Energy and Water Usage Data Key Words actual whole project energy, water usage data, at least 5 years, supplying information, regular basis, free, accessible, secure, online tool, collection of information, service or utility providers Request Type Descriptive Proposed Data Type Yes or No; Text Proposed Submittal Checklist; LEED Online template; Attachments

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98 Table 5 1 3 Interpreting report of MPR7 Item Description LEED Category MPR 7 : Must Comply with a Minimum Building Area to Site Area Ratio Key Words gross floor area, project building, no less than 2%, gross land area, project boundary Request Type Quantitative Proposed Data Type Numeric; Logic al Proposed Submittal Calculation ; LEED Online template LEED c ategories There are 5 major environmental categories (SS, WE, EA, MR and IEQ) in the LEEDNC 2009 rating system plus 2 supplemental categories (ID and RP) As reviewed previously, each LEED category consists of several credits with a certain number of points assigned. M eanwhile compliance with one or more prerequisites is mandatory without any point attainable for each category except for the Innovation and Design (ID) and Regional Priorities (RP) Due to the diversity of building types, geoclimatic factors and owners project requirements, the LEED rating system allows a certain level of flexibility to the project team by providing compliance options for some credits. T he compliance options constitute the requirements for the credit, and enable the project team to satisfy the credit with multiple choices Depending on the level of complexity, one option may be worth more points than others. So the project team has to dec ide what tradeoff to make when pursuing certain LEED points, based on factors such as cost, availability of resources and technology readiness, to name a few. The requirements interpreting process of the actual LEED credits is similar to that in the MPRs. Extra care needs to be taken for the submittal part. Unlike the MPRs, the submittals for the LEED credits are much more complicated. There are actually two type of requirements interpretation. The first type is for the credi t requirements and the second is for the submittal requirements. The interpretation of the credit requirements

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99 deal s with the data request to achieve compliance while the interpretation of submittal requirements aim s to demonstrating the achieved compliance. Tables 5 1 4 to 516 exemplify three different scenarios in the interpretation process: Table 51 4 deals with the Prerequisites of LEED credits ; Table 51 5 deals with Credits without Options; and Table 516 deals w ith Credits with Options. Table 51 4 Prerequisite interpretation report of SSp1 Item Description LEED Category SSp1 : Construction Activity Pollution Prevention Requirements Key Words 2003 EPA c onstruction g eneral p ermit local standards, National Pollutant Discharge Elimination System (NPDES) program Request Type Descriptive Proposed Data Type Yes or No ; Text Submittal Requirements Project drawings; Confirmation of NPDES compliance; Narrative ; LEED Online template Submittal Data Type Image; Boolean; Text Table 51 5 Credit (without Option) interpretation report of SS c1 Item Description LEED Category SS c1 : Site Selection Requirements Key Words d o not develop, prime farmland, lower than 5 feet above the elevation of the 100-year flood, habitat for federal or state threatened or endangered lists, 100 feet of any wetlands, undeveloped land that is within 50 feet of a water body, public parkland Request Type Descriptive and quantitative Proposed Data Type Yes or No; Submittal Requireme nts Confirm compliance with criteria ; Narrative ; LEED Online template Submittal Data Type Image; Boolean; Text Table 516. Credit (with Option) interpretation report of SSc2 Item Description LEED Category SSc2 : Development Density & Community Connectivity Requirements Key Words Option 1: development density, previously developed site, minimum density of 60,000 square feet per acre net; Option 2: previously developed site,1/2 mile, average density of 10 units per acre net, 10 basic services, pedestrian access Request Type Descriptive and quantitative Proposed Data Type Yes or No; Numeric Submittal Requirements Option 1: Site vicinity plan ; Site/Building area ; Development density; LEED -Online template Option 2: Site vicinity plan; Site/Building area; List of business; Narrative; LEED Online template Submittal Data Type Image; Boolean; Numeric; Text

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100 A complete interpretation report for the LEED MR category is shown in Tables 5 17 to 525. The results identify key words in a LEED credit requirement description and determine if descriptive or quantitative data are needed. Then the submittal requirement of this credit is also analyzed and interpreted, following the same methodology. Table 51 7 Prerequisite interpretation report of MR p1 Item Description LEED Category MRp1 : Storage and Collection of Recyclables Requirements Key Words easily accessible, dedicated area, recycling, minimum, paper, corrugated cardboard, glass, plastics and metals Request Type Descriptive and quantitative Proposed Data Type Yes or No ; Numeric Submittal Requirements Recycling plan; Floor plan/site plan with recycling storage area ; LEED Online template Submittal Data Type Image; Boolean; Numeric; Text Table 51 8 Credit interpretation report of MRc1.1 Item Description LEED Category MRc1.1 : Building Reuse Structural Requirements Key Words existing building structure, envelope, area percentage, 55%, 75%, 95%, addition less than 2 times square footage of existing building Request Type Descriptive and quantitative Proposed Data Type Numeric ; Logical Submittal Requirements Table of existing and reused square footage; For addition, confirm meeting square footage requirements; LEED Online template Submittal Data Type Numeric; Logical; Text Table 51 9 Credit interpretation report of MRc1.2 Item Description LEED Category MRc1.2 : Building Reuse Non structural Requirements Key Words existing interior nonstructural elements, at least 50% by area, addition less than 2 times square footage of existing building Request Type Descriptive and quantitative Proposed Data Type Numeric; Logical Submittal Requirements Table of existing and reused square footage; For addition, confirm meeting square footage requirements; LEED Online template Submittal Data Type Numeric; Logical; Text

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101 Table 520. Credit interpretation report of MRc2 Item Description LEED Category MRc2 : Construction Waste Management Requirements Key Words r ecycle and/or salvage, nonhazardous, construction and demolition debris, construction waste management plan, 50%, 75%, weight or volume Request Type Descriptive and quantitative Proposed Data Type Numeric; Text Submittal Requirements Calculation tables; Location of landfill/receiving agents; Construction waste management pl an ; LEED Online Template Submittal Data Type Numeric ; Text Table 52 1 Credit interpretation report of MRc3 Item Description LEED Category MRc3 : Material Reuse Requirements Key Words salvaged, refurbished or reused materials, permanently installed, 5% or 10%, based on cost, total value of materials, or 45% of total construction cost Request Type Descriptive and quantitative Proposed Data Type Numeric; Text Submittal Requirements Calculation tables; Reuse strategy; LEED Online template Submittal D ata Type Numeric; Text Table 52 2 Credit interpretation report of MRc4 Item Description LEED Category MRc4 : Recycled Content Requirements Key Words recycled content, postconsumer, 1/2 of the preconsumer, 10% or 20%, based on cost, total value of materials, or 45% of total construction cost Request Type Descriptive and quantitative Proposed Data Type Numeric; Text Submittal Requirements Calculation tables; Product vendors and cutsheets ; LEED Online template Submittal Data Type Numeric; Text Table 52 3 Credit interpretation report of MRc5 Item Description LEED Category MRc5 : Regional Materials Requirements Key Words extracted, harvested or recovered, manufactured,500 miles, 10% or 20%, based on cost, total value of materials, or 45% of total construction cost fraction percentage by weight Request Type Descriptive and quantitative Proposed Data Type Logical; Numeric; Text Submittal Requirements Confirmation on regional materials, Calculation tables; Product vendors and cutsheets; LEED Online template Submittal Data Type Logical; Numeric; Text

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102 Table 52 4 Credit interpretation report of MRc6 Item Description LEED Category MRc6 : Rapidly Renewable Materials Requirements Key Words rapidly renewable, 2.5% based on cost, total value of materials, or 45% of total construction cost, 10 year or shorter cycle Request Type Descriptive and quantitative Proposed Data Type Logical; Numeric; Text Submittal Requirements Confirmation on rapidly renewable materials, Calculation tables; Product vendors and cut sheets; LEED Online template Submittal Data Type Logical; Numeric; Text Table 52 5 Credit interpretation report of MRc7 Item Description LEED Category MRc7 : Certified Wood Requirements Key Words 50% based on cost, value of wood based materials, permanently installed, FSC, assembly percentage based on weight, volume or cost Request Type Descriptive and quantitative Proposed Data Type Logical; Numeric; Text Submittal Requirements FSC/COC compliance ; Calculation tables; Product vendors and invoice s; LEED Online template Submittal Data Type Logical; Numeric; Text Screening the BIM Functionality Inventory The functionality inventory of the Revit suite and supplemental applications including GBS, Ecotect from Autodesk, and GIS, Google Earth, etc. have been briefly introduced in previous paragraphs. With the LEED requirements interpreted into data requests, it is time to match up these requests and those functionalities. Again, LEED Materials and Resources will be used as an example. Basically, as previously explained, for each Prerequisite or Credit, there are two kinds of data requests, one for actual compliance and one for demonstrating the compliance, which is the submittal. Tables 5 26 to 534 illustrate the process to explore suitable functionality for compliance and submittal requests respectively. Table 526. Functionality screening for MRp1: Storage and Collection of Recyclables BIM Solution Functionality vs. Compliance Request Functionality vs. Submittal Request Revit Site plan/Floor plan (2D/3D); Decals for recyclables; Site plan/Floor plan; Area calculation (quantity takeoff)

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103 Table 527. Functionality screening for MRc1.1: Building Reuse Structural BIM Solution Functionality vs. Compliance Request Functionality vs. Submittal Request Revit Floor plan by phases (demolish + new construction) ; A rea takeoff by phases for structural components S chedules/ quantities report on structural components by phases Table 5 28. Functionality screening for MRc1.2: Building Reuse Nonstructural BIM Solution Functionality vs. Compliance Request Functionality vs. Submittal Request Revit Floor plan by phases (demolish + new construction); Area takeoff by phases for non structural interior components Schedules / quantities report on non structural interior components by phases Table 529. Functionality screening for MRc2: Construction Waste Management BIM Solution Functionality vs. Compliance Request Functionality vs. Submittal Request Revit Floor plan by phases (demolish + new construction); Multi -category material takeoff by phases (volume +density factor) Schedules / quantities report on m ulti category material takeoff by phases (volume or weight) Table 53 0 Functionality screening for MRc3: Material Reuse BIM Solution Functionality vs. Compliance Request Functionality vs. Submittal Request Revit Shared parameter* (tag material as reused); Material takeoff and pricing Schedules/quantities report on reused materials; Pricing (material cost only) report Shared parameters are parameters that can be added to families or projects and then share with other families and projects. They give the ability to add specific data that is not already predefined in the family file or the project template. Table 53 1 Functionality screening for MRc4: Recycled Content BIM Solution Functionality vs. Compliance Request Functionality vs. Submittal Request Revit Shared parameter (tag material as postconsumer or preconsumer ); Material takeoff and pricing Schedules/quantities report on recycled contents ; Pricing (material cost only) report Table 53 2 Functionality screening for MRc5: Regional Materials BIM Solution Functionality vs. Compliance Request Functionality vs. Submittal Request Revit Shared parameter (tag material as regional; zip code); Material takeoff and pricing Schedules/quantities report on regional materials; Pricing (material cost only) report Table 53 3 Functionality screening for MRc6: Rapidly Renewable Materials BIM Solution Functionality vs. Compliance Request Functionality vs. Submittal Request Revit Shared parameter (tag material as rapidly renewable); Material takeoff and pricing Schedules/quantiti es report on regional materials; Pricing (material cost only) report

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104 Table 53 4 Functionality screening for MRc7: Certified Wood BIM Solution Functionality vs. Compliance Request Functionality vs. Submittal Request Revit Shared parameter (tag material as FSC certified); Material takeoff and pricing Schedules/quantities report on regional materials; Pricing (material cost only) report Integration Framework Summary The integration framework is basically established on the basis of the LEED requirements interpretation and the BIM functionality screening. Table 535 summarizes this framework in the tabular format Table 53 5 Integration framework summary LEED NC 2009 Autodesk Products Non -Autodesk Products Notes MP R 1 Revit: P roject information MPR 2 Revit: P roject information MPR 3 Revit: Site plan MPR 4 Revit: Floor plan MPR 5 Revit: Floor plan + S hared parameter (FTE) MPR 6 FMDesktop FM: Systems MPR 7 Revit: Site plan + Floor plan SSp1 Civil 3D; Revit: Site plan SSc1 Civil 3D; Revit: Site plan + KML file ArcGIS: L ocal GIS data SSc2 ArcGIS: L ocal GIS data or Google Map SSc3 Revit: Project information SSc4.1 Revit: Shared parameter (Zip code) ArcGIS: L ocal GIS data or Google Map SSc4.2 Revit: Site plan + Floor plan; Shared parameter (FTE) SSc4.3 Revit: Site plan with parking components; Shared parameter (FTE) SSc4.4 Revit: Site plan with parking components; Shared parameter (FTE) SSc5.1 Revit: Site plan SSc5.2 Revit: Site plan with use of property line; Building layout plan SSc6.1 Revit: Site plan ; Civil 3D SSc6.2 Revit: Site plan; Civil 3D SSc7.1 Revit: Site plan with landscaping + parking; Shared parameter (SRI)

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105 Table 535. Continued. LEED NC 2009 Autodesk Products Non -Autodesk Products Notes SSc7.2 Revit: Roof plan; Shared parameter (SRI) SSc8 Revit: Site plan with exterior lighting IES: RadianceIES WEp1 Revit: Plumbing fixture schedules (baseline case + design case) ; Shared parameters (Flowrate + FTE) GBS: Water consumption analysis WEc1 Revit: Site plan with landscaping GBS: Water consumption analysis WEc2 Revit: Plumbing fixture schedules (baseline case + design case); Shared parameters (Flowrate + FTE) GBS: Water consumption analysis WEc3 Revit: Plumbing fixture schedules (baseline case + design case); Shared parameters (Flowrate + FTE). GBS: Water consumption analysis EAp1 Revit: As built model + Product information Very limited EAp2 Revit: Model geometry, rooms, spaces and zones; GBS: Energy simulation IES: Energy simulation EAp3 Revit: Product information; Shared parameters (LCGWP+LCODP) Very limited EAc1 Revit: Model geometry, rooms, spaces and zones; GBS: Energy simulation IES: Energy simulation EAc2 GBS: Energy simulation data IES: Energy simulation data Very limited EAc3 Revit: As built model + Product information Very limited EAc4 Revit: Product information; Shared parameters (LCGWP+LCODP) Very limited EAc5 Revit: MEP products schedule Very limited EAc6 GBS: Energy simulation data IES: Energy simulation data Very limited MRp1 Revit: Site plan with area designation

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106 Table 535. Continued. LEED NC 2009 Autodesk Products Non -Autodesk Products Notes MRc1.1 Revit: Floor plan + Material takeoff by phases (Demolition and New construction) Compute Area MRc1.2 Revit: Floor plan + Material takeoff by phases (Demolition and New construction) Compute Area MRc2 Revit: Floor plan + Material takeoff by phases (Demolition and New construction) Compute Volume or Weight MRc3 Revit: Shared parameter (Reuse) + Material takeoff and Pricing (material cost only) Compute Cost MRc4 Revit: Shared parameters (Post -consumer and Pre consumer) + Material takeoff and Pricing (material cost only) Compute Cost MRc5 Revit: Shared parameter (Regional or Zip code) + Material takeoff and Pricing (material cost only) Compute Cost MRc6 Revit: Shared parameter (Rapidly Renewable) + Material takeoff and Pricing (material cost only) Compute Cost MRc7 Revit: Shared parameter (FSC) + Material takeoff and Pricing (wood products only) Compute Wood Cost only IEQp1 Revit: Space schedule with CFM Limited IEQp2 Revit: Floor plan with designated area Limited IEQc1 Not Applicable IEQc2 Revit: Space schedule with CFM Limited IEQc3 Not Applicable IEQc4 Revit: Tag materials with shared parameter (VOCs) Need manufacturer information IEQc5 Revit: Floor plan (show entryway design) Limited IEQc6.1 Revit: Electrical plan IEQc6.2 Revit: Electrical plan + Operable window schedule IEQc7 .1 Not Applicable IEQc7.2 Not Applicable

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107 Table 535. Continued. LEED NC 2009 Autodesk Products Non -Autodesk Products Notes IEQc8.1 Revit: Shared parameters (VLT and WFR); GBS: Daylighting and View analysis; Ecotect: Solar analysis; IES: Daylighting and View analysis IEQc8.2 Ecotect: Daylighting analysis; 3dsMax: view design IDc1 BIM as education tools BIM as education tools No definitive approach IDc2 Revit: Project parameter (LEED AP) RP1 Revit: Shared parameter (Zip Code) Results: Revit LEED Application Model The integration framework creates the foundation for the Revit LEED application model. As the BIM solutions keep advancing, this framework will need updating and will evolv e accordingly. The application model is LEED project delivery oriented, and the one and only goal is to achieve the LEED certification. Critical stages to be covered by the application model include: Project Planning: the major concern for the model at this stage i s the owners commitment to LEED. Without this commitment, there is no need to execute this application model at all; Design Charette: a major task here is formulating the LEED strategy. The owner and the project team need to figure out which level of certification (literally the first decision is which LEED rating system to us e but here by default is the LEED NC 2009 system) the project is looking for; how many LEED points are desirable; which credits to go after and why; preliminary solutions to achieve these LEED points, etc. A premium tool to use at this stage is the LEED check list; Design Development: obviously, this is the most critical stage in preconstruction. The biggest concern is how to make sure the designers are informed about the LEED requirements, which is often referred as the LEED oriented design. Providing as sistance to designers thus becomes a key function the application model should possess. It is also the stage when the designtype LEED credits should be analyzed. Lots of critical design configuration analysis including energy simulation, solar design, day lighting and view design, and water consumption should be done at this stage;

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108 Bidding: although the Revit LEED application model does not directly involve in the bidding process, the created building information model can help generate contract documentation and conduct constructability analysis; Construction: two major tasks in this stage of the application model include dealing with the constructiontype LEED credits and preparing submittals for pursued LEED points. This is basically the documentation management stage; and LEED Certification Application: at this stage, all the required LEED Online templates and supplemental submittals should have been completed and submitted to USGBC for review. As introduced in the methodology part, the Revit LEED application model consists of two major modules: the design assistance module and the certification management module. The contents, structure, function and applicable stages of this application model are shown in Figure 51 7 In the course of developing the two modules of the application model, it was observed that with some creative combination, existing features in Revit could be manipulated to provide designers and contractors with new functionalities. Revit by nature is an authoring tool while the project delivery on the other hand is a much more comple x management process. How to develop an interface between the Revit platform and critical project management issues in the application model becomes another challenge. The following sections attempt to provide a more indepth description of developing the two modules of the proposed application model In determining the needs of the LEED project team, opinions were obtained from project managers and LEED APs in local Gainesville area through face to face interviews, and were incorporated in the model development.

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109 Figure 51 7 Execute Revit LEED application model in project delivery. Module 1: Design Assistance The most fundamental design assistance for a LEED project is to keep the architects and engineers aware of the requirements of the LEED rating system. It is unrealistic to expect that all designers are familiar with LEED, let alone the requirements details for specific credits. Admittedly, the LEED reference guide could help with this. However, it works much better if the desirable LEED knowledge is integrated into the Revit platform so that the designers can literally be learning while designing. Before the design process starts, the LEED strategy should be formulated and disseminated to the whole project team. Designers need to ensure that the targeted LEED credits have been taken into account when creating the building information

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110 model. As the LEED str ategy keeps updating in conformity with the most recent project information, so does the LEED credits status. The LEED strategy is always the bottom line of the project and all team members should be on the right track to the eventual project goal set up i n the strategy. Again, a most productive manner to integrate this strategy is to make it part of the Revit platform. Through interviews with a project administrator (who was also a LEED AP) on some local LEED projects in Gainesville, Florida, some meaningf ul issues were brought up. A highlighted one was about the material specification, which had actually been touched upon when analyzing the survey results. Lots of contractors have difficulties in finding the appropriate material suppliers since they are not knowledgeable which manufacturers products have recycled contents; which vendors sell salvaged materials; which suppliers products are regional; or which wood products are FSC certified. Besides, they may also have no sources for such information either. Consequently, a yellowpage type directory that captures LEED oriented material suppliers and manufacturers could be a very valuable feature for both designers and contractors. LEED strategy and Revit template The project template in Revit is a handy tool that can be customized to the needs of specific project types. For the Revit LEED application model, a LEED NC 2009 project template is developed. This template is based on the LEED NC v2.2 template provided by Haynes (2008). Figure 518 is the sc reen shot of the LEED NC 2009 template. In comparison with indigenous Revit templates, the customized LEED template provides extra features including: A built in LEED checklist that the project team could use as a starting point for the LEED strategy, with fields such as points achievable and points attempted, the checklist will reflect the targeted LEED certification level;

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111 A collection of LEED credit sheets that the project could put relevant views (floor plan, elevation plan or section plan, etc. are called views in Revit) on to be referenced by the contractors in construction. With as built information feeding back into the building information model, those sheets of views will become important submittals to the LEED certification review proces s; and In order to guarantee the integrity of the LEED checklist, the points validity column marks up the erroneously attempted points in red. Obviously, it is not possible to achieve more points than the maximum achievable points for each category. The detailed steps to create this LEED template are similar to creating ordinary Schedules and Quantities in Revit. All the LEED credit sheets are ordinary Revit drawing sheets with customized Titleblock features. Appendix B gives a stepby step guide to create a LEED NC 2009 template from scratch. LEED knowledge and Revit API Since the LEED rating system and all the credits information are completely external to the Revit environment, it is nearly impossible to count on existing functionalities to achieve the goal of integrating the desired LEED knowledge for the designers. The Revit API provides the solution to internalize external applications into the Revit platform. As specified by the Revit 2010 API Developers Guide (Autodesk 2009), using the API developers can: Gain access to model graphical data; Gain access to model parameter data; Create, edit, and delete model elements like floors, walls, columns, and more; Create add ins to automate repetitive tasks; Integrate applications into Revit based vert ical products. Examples include linking an external relational database to Revit or sending model data to an analysis application; Perform analysis of all sorts using BIM; and Automatically create project documentation.

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112 Figure 51 8 The LEED NC 2009 Revit project template. (Source: developed on basis of Haynes 2008).

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113 The Revit API is compatible with any Microsoft .NET compliant language including Visual Basic.NET, C#, and C++/CLI. To create a Revit API based addin, the developer must provide specific entry point types in the addin DLL. These entry point classes implement interfaces, either IExternalCommand or IExternalApplication, which require modifying the Revit.ini file. In this w ay, the addin will run automatically for certain events or manually from the Revit External Tools menubutton. Figure 519 illustrates the relationship and interconnection between the Revit platform, Revit API and the Addins. Figure 51 9 Revit, Revit API and AddIns. (Source: Autodesk 2009). The addin created by inheriting the interface IExternalCommand appears as a line item listed in the External Tools button in the Revit program. Figure 520 shows the steps to modify the Revit.ini file to create the desired entry point for the sample addin HelloWorld

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114 [ExternalCommands] ECCount=1 (The ECCount stands for how many external commands are already in the Revit program) ECClassName1=HelloWorld.Class1 ECAssembly1=C: \ Sample \ HelloWorld \ bin \ Debug\ HelloWorld.dll ECName1= HelloWorld ECDescription1=Implementation of Hello World within Autodesk Revit Figure 520. HelloWorld addin. However, in order to make the sample HelloWorld addin displays similar to existing Revit applications, a ribbon panel needs to be created inheriting the IExternalApplication interface and which should execute the HelloWorld DLL. The Revit.ini file then needs to be modified as shown in Figure 521. [ExternalApplications] EACount = 1 (The EACount stands for how many external applications are already in the Revit program) EAClassName1 = AddPanel.CsAddPanel EAAssembly1 = C: \ Sample \ AddPanel \ AddPan el \ bin \ Debug \ AddPanel.dll Figure 521. Modify Revit.ini. To provide designers with the LEED knowledge, essentially including the credit requirements and the submittal requirements, a group of LEED reference guide based normative documents are embedded into the Revit platform through the API development. These documents are PDFs (portable document format) that will be opened through the developed LEED oriented ribbon panels as external applications. A ppendix C shows the process to create a LEED Project Information panel that hosts the MPRs, Project Summary Details, Occupant and Usage Data, and Schedule and Overview Documents, which are the four preliminary LEED Online forms to be submitted for certification review. The programming language is Visual C#, and the tool used is Microsoft Visual Studio 2008.

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1 15 The created LEED Project Information Panel is presented in Figure 522. With similar metho dology, all the desirable LEED knowledge can be integrated into the current Revit authoring environment to help the designers make LEED informed design decisions. The contents of the LEED knowledge may not be limited to the generic credits or submittal inf ormation. It is more meaningful when the design company digests the USGBC LEED knowledge with their in house knowledgebase from previous LEED project experience. The combination of the customized LEED project template, the LEED drawing sheets and the inter nal LEED knowledgebase constitutes quite powerful design assistance to the architects and engineers. The flexibility of the Revit API is also valuable for use in the heterogeneous environment in the AEC industry. Module 2: Certification Management LEED certification management is the project management tailored to deal with the certification process. Major management issues include generating documentation, collecting and managing submittals, and streamlining the application for certification. To be more specific, the documentation generation needs to take care of all the required calculations and narrative to demonstrate compliance with the attempted LEED points. The submittal collection and management needs to capture all the critical submittals that ar e required as supplemental evidence to the LEED point application, such as certificates, manufacturers cut sheets and invoices, etc. Finally, once the project team is ready to submit the application for certain LEED credits, the corresponding LEED Online template should be prepared and submitted to GBCI for review. Since normally each LEED credit will be assigned to a certain project team member, it becomes necessary to monitor the responsible party for the particular LEED credit, and track the status and potential issues raised in the project delivery.

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116 As noted earlier in the discussion of the integration framework, there are two types of LEED credit requirements: descriptive and quantitative. For descriptive credit requirements, the documentation to demonstrate compliance often involves drawings, and narratives. For quantitative credit requirements, a certain amount of calculation is usually expectable. Bearing in mind that a calculation is always based on the existing project information, it is thus possi ble to take advantage of the building information model to perform most of the calculations using features/tools built in Revit. Schedules/ Q uantities is one such tool most frequently used. A S chedule/ Q uantity table is a summary of a range of relevant i nformation for the model com ponents in a specific category, and the table is interactive with the graphical representation of the same model component. Whenever a change is made to the model component, the table will update correspondingly, vice versa. The categories in Revit are collections of interrelated family types of building components. For instance, the category Windows captures all window instances in the model, regardless of the shape, size, materials and other features of the window. For each c ategory, there are definitive parameters, which are called fields, to comprehensively describe the characteristics of a model component. Again taking Windows for example, the available fields range from the actual physical properties of the window to t he installation detail, manufacturer, cost and quantity, to name a few. More importantly, if the project team wants to attach more details, Revit is flexible in allowing customized parameters to be added into existi ng schedules/quantities fields. Arguably, the most valuable parameter to add is the so called Shared Parameter.

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117 Figure 52 2 Create a LEED project information addin through Revit API.

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118 LEED calculation using shared parameter In Revit, the purpose of using a shared parameter is always associated with adding specific data that is not already predefined in the families or projects. The appropriate circumstances to use shared parameters for LEED credits compliance have been identi fied in the integration framework summary. The Materials and Resources category turns out to be the best case for the application of shared parameters. Terms such as Reused, Post consumer, Pre consumer, Regional, Rapidly Renewable and FSC speci fy the materials LEED features, and should be defined in the LEED project template in Revit. Appendix D shows a detailed example of creating the Post consumer as a shared parameter, and using it to perform the calculation for the MRc4: Recycled Content. LEED certification management using web based application The advantage of a web based application rests in its capacity to enable communication between project team members geographically apart. When it comes to information management, the major barrier in current practice is the inconsistent data input from different sources. This is especially true in the LEED certification process when every entity is trying to prepare the desirable documentation for the LEED credits. With an integrated and elaborately designed web application, all project members are required to upload key documents following a standardized and well controlled process. Possible errors and exceptions will be identified and tackled before damage is done to the integrity of the core project information. To be more substantial, there are two scenarios to take into account in regard to the implementation of this webbased certification management system:

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119 Design credit scenario: A fter the building information model is created, the project team might choose to apply for design phase submission of the applicable credits. Relevant submittal documents will be generated while the LEED Online templates are filled. However, USGBC will not award any credits until the final certification review. The pr oject team definitely needs to backup all pertinent documents for these design credits somewhere, and expect them to be potentially updated or modified as the project progresses; and Construction credit scenario: O nce the project kicks off, the general contractor and sub contractors become the major players. Typically, the general contractor is in charge of collecting, tracking and managing all pertinent project information from sub contractors in addition to their inhouse documentation. At the time when a construction type credit is ready for submission, the general contractor is also obliged to check on the readiness and quality of the associated documentation. Catering to the needs of the two scenarios, the proposed web based certification management application should possess the following features: User control: T he application should define the different access levels to keep the project information secured and integrated; Friendly user interface: T he application should carry an easy understandable int erface for the user to navigate through; Robust functionality: T he application should allow document uploading and downloading, updating and sharing between authorized project team members; Powerful database infrastructure: T he application should support automation of information acquisition and processing for the LEED certification purpose; and Maintenance flexibility: T he application should allow for future expansion and enhancement to accommodate possible changes made to the LEED rating system or the BIM solution tools. The selection of tools to create this web application requires extra prudence considering the interoperability issue in the course of data input/output. Currently, Revit supports direct data export through ODBC to Microsoft Access and Micr osoft Excel. However, both Microsoft Access and Excel are not widely used as database infrastructure in web applications. A prevalent software bundle for database supported web application development is called WAMP (Windows, Apache, MySQL and PHP),

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120 where Windows is the operating system, Apache is the web server, MySQL is the database and PHP is the web scripting language. In comparison with hard coded web applications, using database support will make the maintenance much easier since no scripting will be involved but only simple updates at the data level. For a web application designed for building information modeling, this is an advantage. Designing the web application is an intricate process. The real challenge is not from the programming requirement but the architecture of the application. The architecture makes sure that the user will follow easily understandable procedures to perform certain task s, while the database supplies desired information to the expected outcome after running the web application. Figure 523 illustrates the architecture of the proposed web application. Notice for the database part, MySQL is the direct data infrastructure of this web application. All information contained in the Project Module and LEED Module could be arranged into a MySQL database. Meanwhile, for the BIM Module, it is possible to e xport the Revit internal database through ODBC into a predefined MySQL database. Revit as a BIM authoring tool has both a graphical user interface that sits on top of a database. In essence, any instance of the model components is supported by a certain am ount of data. Schedules/quantities are simply more apparent evidence of the existence of the database. Depending on the tasks that the user is performing, the Application Service triggers the query in MySQL to manipulate the database and generate the des ired results. To develop the MySQL database for the web application, it is necessary to sort out the relationships between different data fields. MySQL is a relational database, which

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121 Figure 52 3 Architecture of the proposed certification management web application. means the constituent components of it are basically interrelated tables. Each table is a collection of immediately relevant information. Tables are composed of rows and columns. In database language, each column is a field and each row is a feature In between the tables, the relationship is built through the use of two types of keys, the Primary Key and the Foreign Key. A primary key is used to uniquely identify each row in a table, while a foreign key is a field (or combination of fields) that points to the primary key of another table. The purpose of the foreign key is to ensure referential integrity of the data. In other words, only values that are supposed to appear in the database are permitted.

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122 With careful research on the LEED certification process, and advice from the LEED AP interviewed, a series of tables for the Project Module and LEED Module were created and made interrelated into a MySQL database. Figure 524 illustrates the relationship between these tables. The goal is to extract the internal data in the building information model systematically from the Revit environment and to integrate it into the web application. This is a comprehensive data export in contrast to the single schedule/quantity or material takeoff export. It is done through the ODBC and eventually will save all the project data (a number of relational tables) into a MySQL database. Appendix E demonstrates this process, again using the small structural framing that was created previously. The maj or validation task at this point is to find out through the ODBC export, whether all the information including the calculated recycled content value in the structural framing material takeoff will be available or not. Unfortunately, the current Revit ODB C export does not fully extract the user defined data. Instead, it strictly controls the export with predefined tables and data types. In addition, the ODBC export in Revit by default adopts the metric measurement system (see marked up area in Figure E 2), thus using the exported data to perform any kind of calculation occurs at the users own risk since the AEC industry in the U.S. still uses the imperial measurement system. This virtually devalues the building information model as a shared data source for the LEED project. Consequently, with current software solutions, it is still challenging to make truly seamless information exchange happen between applications. One of the major objectives for this research is to identify such gaps in current industry software and make appropriate recommendations for future improvement Back to the web

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123 application development, now with the MySQL database created for the Project Module and the LEED Module as shown in Figure 52 4 it is still possible to create a valuab le certification management tool for the project team. The actual process will be elaborated upon in the LEED MR Use Case. Results: LEED Materials and Resources Use Case The use case is a simulation of implementation of the Revit LEED application model in an actual project delivery environment. A simple renovation project is modeled in Revit as a generic building project for analysis in this use case. Considerable constraints were put in place due to the limitation of the application model as well as limitations in Revit functionality. The development process followed the steps in Figure 4 2. Discussions and evaluations were conducted along with the simulation process. Owners Commit ment to LEED At this stage, the owner meets with the project team and they decide to pursue the LEED certification under the LEED NC 2009 rating system. Then a LEED strategy is formulated specifying the certification level and the target LEED credits and points. The project is also registered with USGBC and LEED Online access is assigned to the project team. The project then kicks off, which also triggers the Revit LEED application model. MPRs and Prerequisites Since the compliance with MPRs and prerequisites is mandatory, the project team should make sure that those MPRs and prerequisites are well understood. Parts of the LEED knowledge plug ins were created to deal with this issue. In the Revit API introduction part, a Project Information panel has been created and codes have also been provided. The Project Information panel has dropdown lists of the MPR

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124 Figure 52 4 Relational tables for the certification management web application.

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125 requirements and the associated LEED Online tem plates to be reviewed and filled by the project team. Although these prerequisites are mandatory, they are rudimentary requirements that are relatively easy to comply with. Materials and Resources : Requirements vs. Functionalit ies Once the MPRs are taken care of, the project team enters the stage of determining eligibility for actual credits. Through collaboration between the designers and contractors, approaches towards specific credit achievement are sorted out. In the Materials and Resources category, i t takes both design and construction efforts. The first thing the project team wants to do is to interpret the credit requirements as done in the integration framework process. Second, the project team would like to investigate BIM software they are using for the project and find out if the functionalit ies of the software are sufficient to provide solutions to these requirements. If it does, an action plan needs to be created; if it does not, what is the next step? The cost s to purs u e certain LEED points sometimes trump the technological consideration. So i t is assumed that in this use case the project team wants to fully explore the MR category no matter what costs could be. The MR credits requirements vs. Revit functionality invent ory is summarized in Table 536. Materials and Resources: Execute Revit LEED Application Model The two modules for the MR category are quite straightforward. As suggested by Table 536, most of the requirements calculations can be done though the internal functionalities of Revit. The submittals could be prepared through the created LEED NC 2009 project template as well. In regard to the two modules of the application model, further details of the execution process are discussed below.

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126 Table 536. Prepare the Revit LEED application model for MR credits LEED Credit LEED Requirements LEED Submittals Proposed BIM Solutions Notes MRp1 Recycle 5 basic materials in designated recycling area Site plan; confirmation on materials recycled Revit site plan with recycling area; narrative on recycled materials MRc1.1 Reuse building structural elements (75% or 90%) by area Calculation of reused area (percentage) Two phase quantity takeoff; calculation Phase: existing and Phase: new construction MRc1.2 Reuse building nonstructural elements (50%) by area Calculation of reused area (percentage) Two phase quantity takeoff; calculation Phase: existing and Phase: new construction MRc2 Divert construction waste from landfill (50% or 75%) by weight or volume Compute percentage of total waste diverted by volume or weight ; tipping ticket or other proof Two phase quantity takeoff, calculation Phase: existing and Phase: new construction MRc3 Salvage, refurbish and reuse materials (5% or 10%) by cost Calculation of reused materials cost; percentage out of total material cost Tag material using shared parameter Reuse; material takeoff MRc4 Recycle d (post consumer or pre consumer) content value (10%, 20%) Calculation of recycled contents v alue; percentage out of total material cost; product cut sheets indicating recycling percentage Tag material using shared parameter Post or pre consumer; material takeoff MRc5 Use regional material (within 500 miles) more than 10% or 20% (by cost) Calculation of regional material value; percentage out of total material cost Tag material using shared parameter Regional; material takeoff Zip code s of the project and the products may be useful MRc6 Use rapidly renewable material more than 2.5% (by cost) Calculation of rapidly renewable material value; percentage of total material cost Tag material using shared parameter RapidRenew ; material takeoff MRc7 Use FSC certified wood more than 50% (by cost) of total wood material cost Calculation of FSC certified wood value; percentage of total wood material cost; FSC or COC certificate Tag material using shared parameter FSC; material takeoff

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127 Module 1 execution: Design assistance for MR To incorporate more environmentally friendly products into the project building information model while avoiding the depletion of natural materials, designers need to understand the strategies spelled out in the LEED rating system to encourage use of salvaged, recycled or refurbished material. Transportation of construction materials has considerable impacts on energy consumption globally. Materials that can be regenerated rapidly are much more sustainable than those that do not. Use of FSC certified wood contributes to better management of wood resources as well as fostering social economic justice. The LEED reference guide is the most authoritative source of assistance for the project team. It delivers the USGBCs perspective as to what is the accurate understanding of the rating system. With the reference guide built into the Revit environment, it is expected that the productivity and efficiency of LEED oriented design will be improved. With Revit API, through the IExternalCommand and IExternalApplication interfaces, a group of LEED knowledge panels for the MR category are created and attached to the Revit solution as addins ( see Figure 525). The C# codes for these panels are shown in Appendix H A unique opportunity to assist the architects and engineers in the LEED project design will be to provide them with a comprehensive LEED material library. This library will directly interact with the material vendors or product manufacturers websites with level of details tailored to the LEED rating system. For instanc e, when the architects designate the insulation for a wall, instead of picking up a generic type they will be able to get access to a series of insulation materials with actual manufacturers information including whether it uses rapidly renewable material or whether it has recycled

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128 Figure 525 Module 1: Design assistance for MR credits.

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129 contents, etc. Creating such a comprehensive library obviously is out of the scope of this research, but the concept is worth further investigation by software companies and material suppliers Module 2 execution: LEED calculation using phasing and shared parameter s Major tasks in certification management include the LEED calculation and submittal documentation management. MRp1 is simple enough to allow the use of a site plan to demonstrate the compliance ( see Figure 526). For the rest of the MR credits, most calculations can be done inside Revit using schedules/quantities or material takeoff, which are basically spreadsheet type tables. However some innovations will be needed to customize these generic tables in Revit. The first innovation is to attach the time factor with schedule/quantity, using the P hasing function in Revit The second one is the use of shared parameters that have been briefly introduced in the previous chapter s. Phasing is especially useful for renovation projects. It allows the designers to conveniently visualize the difference between the existing conditions and the new construction. In regard to the LEED rating sys tem, MRc1.1, MRc1.2 and MRc2 all involve comparison between existing and new conditions. Appendix F uses a simple example to delineate using the combination of phasing and schedules/quantities to perform the required calculation for these credits. In this demonstration, only walls (exterior and interior) will be demolished to simplify the calculation. However, the methodology is applicable to more complex real world scenarios. The rest of the MR credits, including MRc3 to MRc7, all deal with unique material properties that contribute to sustainability. These properties are not predefined in the Revit platform and thus require customization by the project team. Shared parameters

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130 turn out to be very efficient to accommodate these needs. Simply put, in order t o calculate the value of materials that satisfy a certain criterion, which could vary from reused, recycled, regional, rapidly renewable to FSC certified, it is desirable to tag the materials in the building information model with such features Figure 526 S ite plan to demonstrate recycling area for compliance with MRp1. All the desired shared parameters for the MR category have been created when conducting the demo calculation for the recycled content value of the sample structural framing project. Appendix G will go through all these shared parameters using simple demonstration. At this point, all the required calculations for the LEED MR category have been completed. In a real LEED project the magnitude and complexity of the calculation wi ll be at a different level, but the basic principles used in the demos will still apply. At the moment when the submittals are being collected to foster the appl ication for these credits to GBCI all the schedules/quantities created for calculation can be easily imported into the LEED credit sheets prepared when creating the LEED template in Revit, and become part of the submittal documentation.

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131 During the development of these shared parameters MRc5: Regional Materials is an interesting case. It is noticed that in order to tag certain products as Regional, the project team needs to know where the material suppliers are located, and how far they are from the projects location. To resolve this problem, a distance calculator is created and embedded in Revit as part of the design assistance module. This distance calculator simply takes two parameters: the zip code of the projects location, and the zip code of the building product. Then with a simple click of the button, the distance between the two zip codes is calculated and the result is displayed in miles. Since zip codes are commonly available information for all building products, it becomes handy for the project team to use this calculator to determine whether or not a product is regional. Figure 527 i llustrates the calculator application. The actual programming code for this application has largely been developed by Smith (2008) (see Appendix H ) Figure 527 Distance calculator using zip codes for MRc5: Regional Materials.

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132 So far all the calculation conducted for these LEED credits in the MR category is generic and model based. This brings up the question about the credibility of these calculation results. The following paragraphs use LEED MRc1.1: Building Reuse Existing Walls, Floors a nd Structural Roofs as an example to further explain the application model implementation process. It also helps preliminarily validate the results generated by the application model. The simple Revit m odel is used again, with certain por t ion of the exteri or wall to be demolished. By designating Existing, New and Complete phases to the model, three interdependent wall schedules (Figure 528) are created so further calculation can be conducted based on these schedules. The formula to calculate reused w all area is as follows: Percentage = {[Exterior Wall Area (Complete)][Exterior Wall Area (New)]} 100% [Exterior Wall Area (Existing)] Figure 528. Use Phasing to attach the time dimension to wall schedules.

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133 In order to validate the r esults, a model based calculation (Table 5 37) is compared with the manual calculation (Table 538). The results from each method turn out to be consistent. But the model based calculation is much more straightforward since all the quantities are automatic ally generated. This can potentially prevent team members making mistakes from omitting certain building components (e.g. forget to deduct window openings from wall area) when conducting manual takeoff. Although in a real LEED project the calculations can be much more complex the fundamental principles of these calculations are still applicable. Table 537: Model b ased calculation for MRc1.1 Building R euse Building Shell/Structure Existing Area (SF) Reused Area (SF) Percentage (%) Reused Structural Floor 4504 4504 Exterior Wall 2478 1952 Roof Structure 5003 5003 Total 11985 11459 95.6% Table 538: Manual calculation for MRc1.1 Building R euse Building Shell/Structure QTO Structural Floor Exterior Wall Roof Structure Total Existing Gross Area (SF) 4500 2700 5004 Opening Area* (SF) 0 222 0 Net Area (SF) 4500 2478 5004 11982 Reused Gross Area (SF) 4500 2100 5004 Opening Area* (SF) 0 165 0 Net Area (SF) 4500 1935 5004 11439 Percentage (%) Reused 95.5% With the information from these schedules/quantities and calculation tables, the project team can easily prepare the corresponding LEED Online template for MRc1.1. There also management efforts are required to make sure in actual construction process, for instance, responsible contractors should keep track of the areas of the actual demolished walls, and make sure that actually match the calculated results

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134 obtained from the Revit model. Figure 529 describes the suggested procedures for complete application model im plementation process. Figure 529. Suggested application model implementation procedures. Module 2 execution: LEED certification management using web application When the Revit LEED application model proceeds to this step, all the MR credit requirements should have been fulfilled. Along with the LEED project delivery process, a large amount of project documents are to be generated and managed for submission to GBCI for review. The LEED Online templates and the supplemental documents for each MR credit obviously are the most critical ones. The web application is a stepby step guidance and data server for the LEED project team to manage the certification process. With different access levels to the web application, team members could upload, download, update and submit relevant documents for the LEED credits assigned to them. As previously described, there are two modules in the web application architecture: Project Module and LEED Module. Accordingly, the execution of the web application has two stages:

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135 Stage 1: The user will login with assigned username and password, and fill in general project and personal information relevant to the LEED project. Then a list of questions will be asked to help the user review some critical issues about the credits assigned to them, starting from the credit information such as credit intent, requirements, reference standards, exemplary performance, to required submittal requiremen ts. This is to verify that the users fully understands their obligation especially the information expected from them to support the corresponding LEED credit application; and Stage 2: T he web application provides functionalities catering to the ordinary f ile systems that support upload, store, download and update of LEED Online templates and other pertinent submittals. The web application operates on top of the MySQL database, and is powered by the Apache Web server, using PHP for server side scripting. I t is intelligent since depending on the inputs at a previous step, the user will be directed to a different ensuing step, which is controlled by the web designer with direct data population from the MySQL database underneath the browser interface. Meanwhil e, with the embedded features in web browsers, project members can easily perform printing, sending emails or other everyday communication activities. Figure 530 presents the preliminary user interface of this LEED certification management web application. It is however not the major concern of this research to fully develop this application considering that the only part left is the programming. Once the credits are ready and submitted to GBCI for review, the work platform will transfer to the LEED Online website. However, this web application can still contribute to the LEED certification process by archiving the documents and potentially provide back up evidence for further details if required by the GBCI reviewers. At this point, the use case for LEED Materials & Resources category is officially completed.

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136 Figure 530 User interface of proposed LEED certification management web application.

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137 Discussion: Code Checking for LEED Certification The concept of code checking has been briefly introduced in the literature review. The International Code Council (ICC) is leading the global efforts to promote automated building code checking by model checking software such as CORENET eplan checking system, Solibri Model Checker and AEC3s BIMService. In order to tackle the heterogeneous environment in the AEC industry, ICC has been dedicated to IFC model based code checking. The major components in this IFC centric process and the fundamental workflow are illustrated in Figure 530. Suppose that the code to be checked is LEED or other green building rating system, this workflow then becomes a sustainability checking system. Figure 53 1 Components and workflow in an IFC based code checking.

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138 Howev er, to realize the automated LEED checking process for the purpose of achieving LEED certification, this code checking approach is still problematic due to the following constraints: First and foremost, the LEED rating system is not yet a standard or a code, its legitimacy as the scientific guidance to green building is still to be justified; Current IFC schema is a very general framework while every single building project is unique. This discrepancy causes inevitable loss of project information during the conversion from BIM authoring format (e.g. Revit format) to the IFC model that will be checked by the code checking engine; The dictionary in the code checking process interprets the important ontology and semantic information between the RuleSets and the IFC model. However, current dictionary framework such as the International Framework for Dictionaries (IFD) is far from complete. This discrepancy causes omissions in the code checking process against certain RuleSets, which might be extremely critical to the quality control of the IFC model being check ed; The format of the compliance report now is very limited and not user friendly. For LEED projects, it will be a huge barrier if the project team could not interpret the compliance report and use the result to guide the actual project delivery. There will be little value to the LEED project team to go through this relat ively complex process yet get nothing valuable out of it. Despite of the above constraints governmental agencies and the AEC industry have been dedicated to prescribing buildings codes specially conceived for green buildings. The research on the codechec king approach to achieve LEED certification i s ongoing and some significant changes have to take place to make this approach more feasible: The IFC and IFD framework need to keep evolving to accommodate the special need for sustainability, in terms of ontology and semantics. The green building movement has been trans forming the industry in an unprecedented manner, new concepts and knowledge will take some time for the industry to completely absorb and digest into standard practice. E nrich ing the vocabul ary of sustainability and green building in the IFC/IFD framework is a must; New building codes catering to green building regulations need to be more performance based. The automated code checking process relies heavily on the

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139 appropriately interpreted RuleSets, which tend to be prescriptive and whose quality is directly determined by the green building code itself; and The user interface of the code checking software should be improved to account for the needs of ordinary industry players whose IT knowled ge or infrastructure is limited. A m ore user friendly software application is important to promote the adoption of building information and other new construction IT products in the AEC industry

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140 CHAPTER 6 CONCLUSIONS, LIMITAT IONS AND RECOMMENDAT IONS Con clusions This research acknowledged BIM and green building as the two major trends in the AEC industry. Based on that premise it proposed a new strategy for the AEC professionals to achieve popular green building certification such as LEED through the inte gration of BIM and green building rating systems. In response to the r esearch Objective I, the first step taken was to conduct a feasibility analysis survey to investigate the two most fundamental questions in the BIM and LEED integration: 1) What LEED requires; and 2) What BIM can provide. Following that, to fulfill r esearch Objective II, a comprehensive integration framework was established to prepare the theoretical foundation for pragmatic solutions to this integration. The integration framework matched up the LEED credit/certification requirements with the functionality inventory in popular BIM software solutions such as Revit from Autodesk. During the matchup process, the compliance as well as submittal requirements of the LEED credits were analyzed and interpreted into certain data requests, including qualitative and quantitative data types, or both. Then the functionality inventory of BIM software was screened to provide solutions to these data requests. Gaps were identified when there was no immediate functionality available in current BIM software to achieve compliance with certain LEED credits. In response to research Objective III and IV, the Revit LEED application model was created on top of the integration framework to deal with practical problems at the credit level in actual LEED projects. The Revit LEED application model consisted of two modules: Design Assistance and Certification Management to accommodate the

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141 needs along with the LEED project delivery and certification process. The Design Assistance module took advantage of the Revit API to provide the designers with off theshelf LEED knowledge inside the Revit environment to ensure accomplishment of the LEED oriented design. The Certification Management module was a web based a pplication built upon the Apache/MySQL/PHP platform. It focused on the compliance with LEED credits as well as the management of documentation and submittals for certification purpose. Finally, to fulfill research Objective V, the LEED Materials and Resources use case was created to preliminarily validate the Revit LEED application model by simulating the real LEED certification process. Technical details in implementing the Revit LEED application model were delineated using a number of demos. Project teams should be able to take advantage of the results of the use case in real LEED project, apparently at a whole different level of complexity and magnitude. Overall, the research demonstrated that BIM and LEED integration was feasible with considerable constraints. The BIM LEED application model on the other hand, was quite sufficient for the LEED MR use case. The perceived constraints were majorly attributed to functionality limits of the BIM software selected, for instance, the absence of GIS linkage, lack of material library that captures industrial product data, and the immature support for interoperability at database level. There were also constraints due to the intrinsic features of the LEED rating system that are simply not applicable to BIM integration. Limitations The biggest limitation of this research is that the proposed integration framework and application model have never been fully validated in real LE ED projects. This is

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142 also the next immediate step needed to make the results of this research truly helpful to AEC professionals. This study looked only at the integration of BIM and sustainability from the LEED perspective, and only one LEED rating system (LEED NC) was analyzed. The results thus were limited to the LEED instead of the general framework of sustainability. Plus, all the software applications developed in this research were quite generic. More intensive coding will be desirable to turn the results of this study into actual products. Finally, considering the immaturity of the BIM and LEED integration, the technical issues were dominant in this research. Nevertheless, in a real world LEED project, the cost benefit implication of such integration is equally important to determine the best strategy to leverage the certification process using BIM technology. In the course of creating the integration framework, it was noticed that there were still considerable gaps between the LEED credit/certificati on requirements and available functionalities of current BIM software solutions. The advancement of BIM technology needs to keep the momentum and make it possible to deal with more stringent modeling requirements oriented towards sustainability. Conversely the LEED rating system itself is problematic to some degree. A major problem would emerge when the project team decided to game the system, meaning that they made no significant improvement of building performance but somehow managed to achieve the LEED certification. Some of the exi sting LEED credits were quite trivial to buildings green performance (e.g. bicycle racks) while quite a few critical sustainability indicators failed to be incorporated into the LEED system (e.g. carbon footprint) To promot e the AEC industrys transition to green with BIM, a truly performancebased green building standard is desirable. The advent of the green building codes discussed previously is an encouraging sign.

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143 Interoperability is another bottleneck that limits the development of the integration framework. It will also eventually determine the integration level between BIM and sustainability considering that information exchange is the bottom line in project management A huge setback in current interoperability fram eworks such as IFC/IFD is the lack of ontology and semantics to describe the vocabulary of sustainability in a format that can be read and understood by computers. Meanwhile, interoperability support from popular BIM software at the database level is still underdeveloped. Li mitation in support for direct data I/O through the ODBC driver i s hindering the development of more flexible and creative strategies of information exchange between project team members The openness of the software API s also needs to be addressed. Due to the unique circumstances of a project, software users want flexibility to customize the application to better serve their needs in manipulating the model information. APIs provide the critical interface to allow such customization. Recommendations for Future Research Buildings and building systems are complex, interactive and dynamic, especially when perceived as the interface between nature and the human society. Technologies can help configure, control and improve building performance to the level that how much buildings are understood by human beings. Sustainability adds extra dimensions to such understanding. The technologies that accommodate the requirements prescribed by the sustainability principles are advancing all the time, but not at the same pace. Energy is arguably the most well researched area, while indoor environmental quality is still primitively understood by professionals. New issues such as carbon emissions may be also of interest to BIM practitioners. To achieve well balanced building performance, BIM development needs reinforced efforts at the full spectrum of

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144 issues in building design and construction. Desirable researches may include more indepth analysis of implementing BIM in building processes such as commissioning and facility management, or look into specialized BIM technology development tailored to certain building types such as health care or educational facilities. Meanwhile, integrating information technology such as BIM with sustainability principles should be careful and not to eschew from the fundamental goals of promoting the productivity and improving profitability in the AEC industry. Companies, especially small and medium sized, are often reluctant to changes in fear of increased risk and financi al uncertainties. The cost implication of integrating new technology with the companies business strategy becomes a critical research topic to support sound decisionmaking. Stakeholders of the companies may want to know how big the investment is going to be, including software, hardware and training; what returnoninvestment (ROI) rate they can expect; what financial risks and other uncertainties are involved, etc. Once companies are committed to adopt the integrated BIM Sustainability strategy, they need both technical support and more importantly, the managerial support. BIM and sustainability are features of a new business paradigm, so will current project delivery methods still be effective? How will the new integrated project delivery (IPD) help in t he companies adaptation to the new business paradigm? What fundamental changes should be made to the companies existing structuring, operating, staffing and profiting? Those are also imperative questions that need to be investigated.

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145 APPENDIX A FEASIBILITY SURVEY O F BIM FOR LEED CERTI FICATION This survey intends to investigate the possibility of using current BIM authoring tools to facilitate the LEED-NC certification (LEED NC 2009) process, with emphasis on the data extraction and information exchange during the project delivery. As a proof of concept, the result of this survey will be incorporated into the authors doctoral dissertation on BIM for Sustainability in more depth. PART 1: General Questions 1. Please describe your/your companys role in a construction project: a. Owner b. A/E c. General Contractor d. Subcontractor e. Other (Please specify___________________________________________________________) 2. According to National BIM Standard (NBIMS), BIM is the virtual representation of the physical and func tional characteristics of a facility from inception onward. As such, it serves as a shared information repository for collaboration throughout a facility's lifecycle. Under this definition, please describe your/your companys experience with BIM: a. Understand the concept only b. Have purchased BIM authoring tools and started employee training c. Have participated in projects using BIM as reference only d. Have participated in projects partially adopting BIM e. Have participated in projects fully adopting BIM (Pl an, Design, Construction and O & M) f. Other (Please specify___________________________________________________________) 3. Please specify the BIM authoring tool(s) used in your company (select all that apply): a. Revit Suite (Architecture, Structure and MEP) b. Bentley System c. ArchiCAD d. Vico Software e. Vectorworks f. Other (Please specify___________________________________________________________ ) 4. Please describe your/your companys experience with LEED for New Construction and Major Renovation (LEED NC): a. Understand the concept only b. Have inhouse LEED APs but no actual LEED NC project experience c. Have participated in projects that pursued LEED NC certification but failed d. Have participated in projects that pursued LEED NC certification and succeeded e. Other (Please specif y___________________________________________________________ ) PART 2: BIM for LEED 2009 Certification Section 1: Perception Research The following questions enquire about your personal perceptions regarding using BIM authoring tools to facilitate the LEED NC certification process based on your understanding or actual work experience. Currently in the market, LEED NC Version 2.2 (LEED NCv2.2) is the major certification system, but there are lots of concerns regarding the new LEED v3 system.

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146 Due to the fact s that most under construction and completed LEED certified projects use LEED NC v2.2, please answer the following questions based on LEED NC v2.2. Perceptions Strongly Disagree Disagree Somewhat Disagree Neutral Somewhat Agree Agree Strongly Agree Likert Scale 1 2 3 4 5 6 7 1. Current BIM authoring tools have been sufficiently designed to meet LEED NC v2.2 requirements 2. Your company has fully integrated BIM authoring tools in LEEDNC v2.2 project delivery 3. Current BIM authoring tools are effective in preconstruction stage of LEED NC v2.2 projects 4. Current BIM authoring tools are effective in construction stage of LEED NC v2.2 projects 5. Current BIM authoring tools could help formulate strategies targeting LEED credits/points 6. Current BIM authoring tools could facilitate generation and dissemination of design and contract documentation 7. Current BIM authoring tools could facilitate communication and information exchange between project members in LEED project 8. Current BIM authoring tools could facilitate documentation generation and submission as required by LEED NC v2.2 certification process, e.g. LEED online 9. Current BIM authoring tools could help reduce the upfront cost of pursuing LEEDNC v2.2 certification 10. Current BIM authoring tools could increase the overall chances of achieving LEEDNC v2.2 certification Section 2: BIM for LEED NC 2009 Applicability Research The following questions will ask you to project the applicability of implementing BIM authoring tools to streamline the LEED NC 2009 certification process based on your understanding of this new system. By April 27th 2009, the USGBC has finished updating their service to accommodate the new LEED v3 (the whole package i ncluding all the 2009 version of LEED rating systems, see http://www.usgbc.org/DisplayPage.aspx?CMSPageID=1970 for more details), and the most updated LEED NC 2009 rating system can be obtained from USGBC following the link: http://www.usgbc.org/ShowFile.aspx?DocumentID=5546 The following questions are strictly formulated according to the 7 categories in the LEED NC 2009 scor ing system. One criterion you may consider using to determine the capacity of BIM authoring tools

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147 could be how those authoring tools will help in the LEED Online templates preparation, in that LEED Online has been the major interface for communication between the project team and USGBC. LEED NC 2009 Categories and Credits Applicability of BIM Authoring Tools Not applicable Hardly Applicable Somewhat Applicable Moderately Applicable Applicable Highly Applicable 0 1 2 3 4 5 Category 1: Sustainable Sites SSp1: Construction Activity Pollution Prevention SSc1: Site Selection SSc2: Development Density and Community Connectivity SSc3: Brownfield Development SSc4: Alternative Transportation SSc5: Site Development SSc6: Stormwater Design SSc7: Heat Island Effect SSc8: Light Pollution Reduction Category 2: Water Efficiency WEp1: Water Use Reduction WEc1: Water Efficient Landscaping WEc2: Innovative Wastewater Technologies WEc3: Water Use Reduction Category 3: Energy and Atmosphere EAp1: Fundamental Commissioning of Building Energy Systems EAp2: Minimum Energy Performance EAp3: Fundamental Refrigerant Management EAc1: Optimize Energy Performance EAc2: On site Renewable Energy EAc3: Enhanced Commissioning EAc4: Enhanced Refrigerant Management EAc5: Measurement and Verification EAc6: Green Power Category 4: Materials and Resources MRp1: Storage and Collection of Recyclables MRc1: Building Reuse MRc2: Construction Waste Management MRc3: Material Reuse MRc4: Recycled Content MRc5: Regional Materials MRc6: Rapidly Renewable Materials

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148 MRc7: Certified Wood Category 5: Indoor Environmental Quality IEQp1: Minimum IAQ Performance IEQp2: Environmental Tobacco Smoke Control IEQc1: Outdoor Air Delivery Monitoring IEQc2: Increased Ventilation IEQc3: Construction IAQ Management Plan IEQc4: Low Emitting Materials IEQc5: Indoor Chemical and Pollutant Source Control IEQc6: Controllability of Systems IEQc7: Thermal Comfort IEQc8: Daylight and Views Category 6: Innovation and Design Process IDc1: Innovation in Design IDc2: LEED Accredited Professional Category 7: Regional Priority RPc1: Regional Priority PART 3: Comments and Suggestions Thanks for your time! Please feel free to make any further comments or suggestions below that you think will be beneficial to investigate the potential of using BIM authoring tools to facilitate the LEED NC certification process and project delivery: If you have any other enquiries or any relevant research that you would like to discuss with the author, please feel free to contact: Wei Wu PhD Candidate, LEED AP Rinker 341, Powell Center for Construction and Environment Rinker School of Building Construction University of Florida Email: vjwwlc@gmail.com Cell: +1 352 328 7299

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149 APPENDIX B DEMO: LEED TEMPLATE IN REVIT 1. Go to and select New project; 2. Select none for Template file and select Create a new Project template (Figure B1), when prompted, select using Imperial measurement system; Figure B 1. Create new project template in Revit. 3. Go to View, and click on the Schedules dropdown list, select Drawing List; 4. In the Drawing List Properties dialogue box, add Sheet Number, Sheet Name to the Scheduled fields; 5. Click Add Parameter to create new Project Parameter, grouping the newly created Project Parameter under Green Building Properties. The Name, Discipline and Types of the parameters should depend on the actual needs (Figure B2); Figure B 2. Add new Green Building Property into template.

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150 6. Create new LEEDNC 2009 (Common, Yes/No), LEED Category (Common, Text), Points Achievable (Common, Integer) and Points Attempted (Common, Integer) project parameters into the Scheduled fields and finish creating the Drawing List. Of course, some Sorting/Grouping and Formatting could be done to make the Drawing List more organized; 7. Before actual drawing sheets are created, the Drawing List schedule should be empty. So next, go to Sheets in the Project Browser, right click and select New Sheet. Select any Titleblock with the suitable size, and create the new drawing sheet; 8. Right click the newly created drawing sheet, and select Properties. Locate the Green Building Properties to view all the customized Project Parameters created in previous steps. 9. Input the appropriate information into these Green Building Properties, and finalize the other details of the drawing sheet such as the Sheet Number and Sheet Name, and then finish editing (Figure B3); Figure B 3. Create a LEED NC 2009 drawing sheet. 10. Now take a look at the Drawing List schedule again, the newly added drawing sheet with all the fields filled should app ear (Figure B4); Figure B 4. Populate the LEED NC 2009 drawing list schedule. 11. Repeat Step 7 9 to add all the desired drawing sheets and the customized LEEDNC 2009 template will be created.

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151 APPENDIX C SAMPLE CODES: LEED KNOWLEDGE PANEL Create the application inheriting IExternalCommand: using System; using System.Collections.Generic; using System.Linq; using System.Text; using Autodesk.Revit; using System.Windows.Forms; using System.Diagnostics; using System.IO; namespace LeedCertification { c lass piF1:IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ PI \ PIf1.pdf"); return IExternalCommand.Result.Succeeded; } } class piF2 : IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ PI \ PIf2.pdf"); return IExternalCommand.Result.Succeeded; } } class piF3 : IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ PI \ PIf3.pdf"); return IExternalCommand.Result.Succeeded; } }

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152 class piF4 : IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ PI \ PIf4.pdf"); return IExternalCommand.Result.Succeeded; } } } Create the panel inheriting IExternalApplication: using System; using System.Collections.Gene ric; using System.Linq; using System.Text; using Autodesk.Revit; using System.Windows.Media.Imaging; namespace AddPanel { public class CsAddpanel:IExternalApplication { public IExternalApplication.Result OnStartup(ControlledApplication application) { string assembly = @"C:\ REVITLEED \ LeedCertification\ LeedCertification \ bin \ Debug \ LeedCertification.dl l"; RibbonPanel piPanel = application.CreateRibbonPanel("LEED Project Information"); PushButton piF1 = piPanel.AddPushButton("Minimum Program Requirements", "Minimum Program Requirements", assembly, "LeedCertification.piF1"); piF1.Image = new BitmapImage(new Uri(@"C:\ REVITLEED \ Images\ MPR.bmp")); piPanel.AddSeparator(); PushButtonData piF2 = new PushButtonData("Project Summary Details", "Project Summary Details", assembly, "LeedCertification.piF2"); PushButtonData piF3 = new PushButtonData("Occupant & Usage Data", "Occupant & Usage Data", assembly, "LeedCertification.piF3"); PushButtonData piF4 = new PushButtonData("Schedule & Overview Documents", "Schedule & Overview Documents", assembly, "LeedCertification.piF4"); piPanel.AddStackedButtons(piF2, piF3, piF4);

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153 return IExternalApplication.Result.Succeeded; } public IExternalApplication.Result OnShutdown(ControlledApplication application) { return IExternalApplication.Result.Succeeded; } } } Modify the Revit.ini file: [ExternalApplications] EACount=8 EAClassName8=AddPanel.CsAddpanel EAAssembly8=C: \ REVITLEED \ AddPanel\ AddPanel\ bin\ Debug\ AddPanel.dll

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154 APPENDIX D DEMO: SHARED PARAMET ERS 1. Open a new Revit project, go to Manage, click on Shared Parameters, create a new text file to store the new shared parameters to be created, and save (Figure D1); Figure D 1. Create a new shared parameter file Revit LEED.txt. 2. In the Edit Shared Parameters dialogue box, add a new Group of MR for the shared paramet ers to be created for the MR category; 3. Under the new MR Group, add new shared parameters including PostConsumer and PreConsumer, and define the discipline as Common, the data type as Yes/No. Other shared parameters for the MR category may include Reuse, Regional, RapidRenew and FSC (Figure D2); Figure D 2. Add desired shared parameters and groups.

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155 4. Create a small structural framing using wide flange beams (W12x16). In order to normalize the weight for W12x16, open the W12x16 Family for editing, and click on Types to open the Family Types dialogue box (Figure D 3); 5. Add a new parameter Wrev under the Structural to indicate the actual unit weight of the W12x16 beam to 26 pounds/ft. The Wrev is also a shared parameter stored in the RevitLEED.txt. 6. Load the modified W12x16 back to the structural framing, and create a material takeoff for it; 7. Add the fields including Assembly Code, Assembly Description, Family and Type, Cut Length, Material Cost. Notice that the newly added shared parameter Wrev is now available since it is part of W12x26 type properties. Add another shared parameter PostConsumer from the Revit LEED.txt (Figure D 4), since typical steel recycling is post consumer; 8. Add a calculated value Extended Cost ba sed on the formula that Extended Cost = (Wrev / 2000 SF) (Material: Cost 1') Cut Length. This formula will compute the cost of a W12x26 steel beam with a unit weight of 26 pounds/ft and a unit material cost of $9000/ton; 9. Add another calculated valu e RecycledValue based on the formula that RecycledValue = if (PostConsumer, Extended Cost 0.25, 0). This formula will compute the value of recycled contents in the steel beams with a default recycled content percentage of 25% (recommended by USGBC). The if condition guarantees that only W12x26 with post consumer recycled contents will be included in the calculation; and 10. Format the material takeoff to get the total value of the recycled contents of this structural framing (Figure D5). Figure D 3. Edit the steel beam family, and modify the Family Types

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156 Figure D 4. Add proper fields into the structural framing material takeoff.

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157 Figure D 5. Completed calculation for the MRc4: Recycled Contents of the sample structural framing.

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158 APPENDIX E DEMO: REVIT TO MYSQL VIA ODBC Export Revit model data to MySQL through ODBC 1. Go to and select Export, click on ODBC Database; 2. In the Select Data Source dialogue box, select Machine Data Source, and select MySQL5.1 (Figure E1A), then click OK; 3. Specify the MySQL server information, and select the destination database (MRc4) to host the exported data (Figure E1B), then click OK; A B Figure E 1. Set up the ODBC export in Revit. 4. Open the MySQL Workbench to inspect the exported data from the sample model under the database MRc4. Notice that only the Revit predefined tables are presented, even most of them do not bear any data since only structural framing components are created in the sample model. The customized material takeoff for the structural framing is not exported; 5. However, it is still worth looking at the table structuralframing, and all the available fields exported. Obviously, none of the calculated recycled content values are exported; neither do the shared parameters created for the LEED calculations (Figure E2).

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159 Figure E 2. Exported Revit model data in MySQL database

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160 APPENIDIX F DEMO: USE CASE MRC1 AND MRC2 Calculate MRc1 and MRc2 Using Phasing & Schedules/Quantities 1. Open a Revit file with existing building information. By default there are two phases created by Revit (Existing and New Construction). Check the Element Properties of all building components in current model to make su re the Phase Created are set as Existing, and the Phase Demolished set as None. Check the view properties of all the floor plans, elevation plans and 3D view, make sure the Phase filter set as Show All and the Phases set as Existing; 2. Make a copy of the floor plan (e.g. Level 1) where the building components will be demolished. Name the newly created floor plan as Level 1 Demolition. Open the view properties of Level 1 Demolition and set the Phase filter as Show All and the Phase s as New Construction; 3. Use the Demolish command to demolish the building components that no longer needed (e.g. exterior wall and interior partitions), and construct the desired new components into the model (Figure F 1). Notice that demolished compon ents will be marked in dotted lines and new construction will be highlighted in red, other unchanged existing building components are grayed out; 4. Make a copy of the finished floor plan, and name it as Level 1 Complete. In its view properties, set the Phase filter as Show Complete, and the Phases as New Construction (Figure F2); Figure F1. Demolish and newly construct in Revit.

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161 Figure F2. Completed project floor plan. 5. Create a wall schedule, selecting the Phase as Existing (Figure F3). Add these fields into the schedule: Family and Type, Length, Width, Area and Volume. Name the wall schedule as Wall Schedule Existing; 6. Instead of creating a new wall schedule for the phase New Construction, simply make a copy of the exi sting wall schedule, modify the schedules properties and change the Phase Filter into Show Complete and the Phase into New Construction. Rename the duplicated wall schedule as Wall Schedule Complete; 7. Make another duplicate of the wall schedule. This time name it as Wall Schedule New. Set the Phase Filter as Show New, and the Phase as New Construction; 8. Tile the three wall schedules in the view window, notice the difference of the wall areas and wall volumes per family type (Figure F 4); Figure F3. Create a Wall Schedule for phase Existing.

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162 Figure F4. Create wall schedules and assign them different phasing properties.

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163 9. Now to calculate MRc1.1, the reused area percentage of exterior wall is computed as: Percentage = {[Exterior Wall Area (Complete)][Exterior Wall Area (New)]} 100% [Exterior Wall Area (Existing)] 10. To calculate MRc1.2, the reused area percentage of interior wall is computed as: Percentage = {[Interior Wall Area (Complete)][Interior Wall Area (New)]} 100% [Interior Wall Area (Existing)] 11. To calculate MRc2, the total construction waste generated is actually the demolished building components, of which the volume is: Demolished Volume = [Total Wall Volume (Exis ting)] {[Total Wall Volume (Complete)][Total Wall Volume (New)]} With supplemental information of the diverted construction waste (e.g. recycling proof and tipping fee invoices), the percentage of actual diverted construction waste can be calculated as: Percentage = Diverted Waste Volume 100% Total Construction Volume (Demolished Volume)

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164 APPENDIX G DEMO: USE CASE MRC3 MRC7 Calculate MRc3 MRc7 Using Shared Parameters 1. Suppose that part of the wall bricks in this project are salvaged materials. To calculate MRc3: Material Reuse, a wall material takeoff is created with the shared parameter Reuse. Also some housekeeping needs to be done. By setting up a filter, only the bricks display in the wall material takeoff. The created wall material takeoff is shown in Figure G1. The Reused Value is a calculated value that based on the following formula: Reused Value = if {Reuse, [Material: Cost]*[Material: Area/1^2], 0}; The if condition guarantees that only reused bri cks are included into the calculation; Figure G 1. Calculate MRc3 using shared parameter. 2. MRc4: Recycled Content has been c5overed in previous demo, so it will be skipped here; 3. Suppose that all the concrete used in this project are manufactured, retailed and transported within 500 miles, the project can pursue MRc5: Regional Materials. The material takeoff for all the concrete used in this project is created and the shared parameter Regional is used to perform the calculation. Figure G2 summari zes the results; 4. Suppose that all the wall rigid insulation in this project use rapidly renewable agrifiber, the project could attempt MRc6: Rapidly Renewable Materials. Figure G3 summarizes the computing material takeoff of the wall insulations, and the use of shared parameter Regional; and 5. Finally, all the flooring in the project uses FSC certified wood. The project decides to pursue MRc7: FSC certified wood. With the use of shared parameter FSC, the value of FSC certified wood could then be computed. Figure G 4 summarizes the calculation for MRc7;

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165 Figure G 2. Calculate MRc5 using shared parameter. Figure G 3. Calculate MRc6 using shared parameter. Figure G 4. Calculate MRc7 using shared parameter.

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166 APPENDIX H SAMPLE CODES: REVIT LEED APPLICATION MODEL Create Application Inheriting IExternalCommand using System; using System.Collections.Generic; using System.Linq; using System.Text; using Autodesk.Revit; using System.Windows.Forms; using System.Diagnostics; using System.I O; namespace LeedCertification { public class MRp1RatingSystem:IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnos tics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ MR \ MRp1RatingSystem .pdf"); return IExternalCommand.Result.Succeeded; } } public class MRp1Template:IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ MR \ MRp1Template.pdf "); return IExternalCommand.Result.Succeeded; } } // public class MRc1aRatingSystem:IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ MR \ MRc1.11.2RatingSystem.pdf");

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167 return IExternalCommand.Result.Succeeded; } } public class MRc1aTemplate:IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ MR \ MRc1.11.2Template.pdf"); return IExternalCommand.Result.Succeeded; } } // public class MRc1bRatingSystem:IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ MR \ MRc1.3RatingSyst em.pdf"); return IExternalCommand.Result.Succeeded; } } public class MRc1bTemplate:IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ MR \ MRc1.3Template.p df"); return IExte rnalCommand.Result.Succeeded; } } // public class MRc2RatingSystem:IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)

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168 { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ MR \ MRc2RatingSystem .pdf"); return IExternalCommand.Result.Succeeded; } } public class MRc2Template : IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ MR \ MRc2Template.pdf "); return IExternalCommand.Result.Succ eeded; } } // public class MRc3RatingSystem:IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ MR \ MRc3RatingSystem .pdf"); return IExternalCommand.Result.Succeeded; } } public class MRc3Template : IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ MR \ MRc3Template.pdf "); return IExternalCommand.Result.Succ eeded; } } //

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169 public class MRc4RatingSystem:IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ MR \ MRc4RatingSystem .pdf"); return IExternalCommand.Result.Succeeded; } } public class MRc4Template : IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ MR \ MRc4Template.pdf "); return IExternalCommand.Result.Succeeded; } } // public class MRc5RatingSystem:IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ MR \ MRc5RatingSystem .pdf"); return IExternalCommand.Result.Succeeded; } } public class MRc5Template : IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ MR \ MRc5Template.pdf "); return IExternalCommand.Result.Succeeded; }

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170 } // public class MRc6RatingSystem:IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ MR \ MRc6RatingSystem .pdf"); return IExternalCommand.Result.Succeeded; } } public class MRc6Template : IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ MR \ MRc6Template.pdf "); return IExternalCommand.Result.Succeeded; } } // public class MRc7RatingSystem:IExternalCommand { public IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet e lements) { System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ MR \ MRc7RatingSystem .pdf"); return IExternalCommand.Result.Succeeded; } } public class MRc7Template : IExternalCommand { p ublic IExternalCommand.Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements) {

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171 System.Diagnostics.Process.Start(@"C: \ REVITLEED \ LEEDTemplates\ MR \ MRc7Template.pdf "); return IExternalCommand.Result.Succeeded; } } } Create Host Panels Inheriting IExternalApplication using System; using System.Collections.Generic; using System.Linq; using System.Text; using Autodesk.Revit; using System.Windows.Media.Imaging; namespace AddPanel { public class CsAddpanel:IExternalApplication { public IExternalApplication.Result OnStartup(ControlledApplication application) { string assembly = @"C:\ REVITLEED \ LeedCertification\ LeedCertification \ bin \ Debug \ L eedCertification.dl l"; RibbonPanel mrPanel = application.CreateRibbonPanel("LEED Category 4: Materials & Resources"); PulldownButton MRp1 = mrPanel.AddPulldownButton("Prerequsite 1", "Prerequisite 1"); PushButton MRp1RatingSystem = MRp1.AddItem("RatingSystem", assembly, "LeedCertification.MRp1RatingSystem"); PushButton MRp1Template = MRp1.AddItem("Template", assembly, "LeedCertification.MRp1Template"); mrPanel.AddSepara tor(); PulldownButton MRc1a = mrPanel.AddPulldownButton("Credit 1.1 1.2", "Credit 1.11.2"); PushButton MRc1aRatingSystem = MRc1a.AddItem("RatingSystem", assembly, "LeedCertification.MRc1aRatingSystem"); PushButton MRc1aTemplate = MRc1a.AddItem("Template", assembly, "LeedCertification.MRc1aTemplate");

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172 PulldownButton MRc1b = mrPanel.AddPulldownButton("Credit 1.3", "Credit 1.3"); PushButton MRc1bRatingSystem = MRc1b.AddItem("RatingSystem", assembly, "LeedCertification.MRc1bRatingSystem"); PushButton MRc1bTemplate = MRc1b.AddItem("Template", assembly, "LeedCertification.MRc1bTemplate"); PulldownButton MRc2 = mrPanel.AddPulldownButton("Credit 2", "Credit 2"); PushButton MRc2RatingSystem = MRc2.AddItem("RatingSystem", assembly, "LeedCertification.MRc2RatingSystem"); PushButton MRc2Template = MRc2.AddItem("Template", assembly, "LeedCertification.MRc2Template"); Pu lldownButton MRc3 = mrPanel.AddPulldownButton("Credit 3", "Credit 3"); PushButton MRc3RatingSystem = MRc3.AddItem("RatingSystem", assembly, "LeedCertification.MRc3RatingSystem"); PushButton MRc3Template = MRc3.AddItem("Template", assembly, "LeedCertification.MRc3Template"); PulldownButton MRc4 = mrPanel.AddPulldownButton("Credit 4", "Credit 4"); PushButton MRc4RatingSystem = MRc4.AddItem("RatingSystem", assembly, "LeedCertification.MRc4RatingSystem"); PushButton MRc4Template = MRc4.AddItem("Template", assembly, "LeedCertification.MRc4Template"); PulldownButton MRc5 = mrPanel.AddPulldownButton("Credit 5", "Credit 5"); PushButton MRc5RatingSystem = MRc5.AddItem("RatingSyste m", assembly, "LeedCertification.MRc5RatingSystem"); PushButton MRc5Template = MRc5.AddItem("Template", assembly, "LeedCertification.MRc5Template"); PulldownButton MRc6 = mrPanel.AddPulldownButton("Credit 6", "Credit 6"); PushButton MRc6RatingSystem = MRc6.AddItem("RatingSystem", assembly, "LeedCertification.MRc6RatingSystem"); PushButton MRc6Template = MRc6.AddItem("Template", assembly, "LeedCertification.MRc6Template"); PulldownButton MRc7 = mrPanel.AddPulldownButton("Credit 7", "Credit 7");

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173 PushButton MRc7RatingSystem = MRc7.AddItem("RatingSystem", assembly, "LeedCertification.MRc7RatingSystem"); PushButton MRc7Template = MRc7.AddItem("Template", assembly, "LeedCertification.MRc7Template"); return IExternalApplication.Result.Succeeded; } public IExternalApplication.Result OnShutdown(ControlledApplication application) { return IExternalApplic ation.Result.Succeeded; } } } Create Distance Calculator Using Zip Codes using System; using System.Collections.Generic; using System.Text; using System.IO; using System.Xml.Serialization; namespace ZipDistCalculator { public class ZipCode { private string _state; private string _code; private double _latitude; private double _longitude; public double Longitude { get { return _longitude; } set { _longitude = value; } } public double Latitude { get { return _latitude; } set { _latitude = value; } } public string Code { get { return _code; } set { _code = value; } }

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174 public string State { get { return _state; } set { _state = value; } } #region Static methods/variables private static List _codeList; public static List CodeList { get { return _codeList; } set { _codeList = value; } } public static void LoadData(string path) { if (File.Exists(path)) { using (StreamReader reader = new StreamReader(@"C: \ REVITLEED \ ZipDistance\ ZipDistCalculator \ ZipDistCalculator\ ZipCo deData.xml")) { XmlSerializer serializer = new XmlSerializer (typeof(List)); _codeList = (List) serializer.Deserialize(reader); } } else { throw new FileLoadException ("Can't find ZipCodeData.xml!"); } } public static double Distance(string zipCode1, string zipCode2) { ZipCode code1 = _codeList.Find( delegate(ZipCode z) { return z.Code == zipCode1; }); ZipCode code2 = _codeList.Find(

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175 delegate(ZipCode z) { return z.Code == zipCode2; }); if (code1 == null || code2 == null) throw new Argu mentException ("One of the codes does not exist."); double earthsRadius = 3956.087107103049; double latitude1Radians = (code1.Latitude / 180) Math.PI; double longitude1Radians = (code1.Longitude / 180) Math.PI; double latitude2Radians = (code2.Latitude / 180) Math.PI; double longitude2Radians = (code2.Longitude / 180) Math.PI; double dista nce = (earthsRadius 2) Math.Asin( Math.Sqrt( Math.Pow( Math.Sin((latitude1Radians latitude2Radians) / 2), 2) + Math.C os(latitude1Radians) Math.Cos(latitude2Radians) Math.Pow( Math.Sin((longitude1Radians longitude2Radians) / 2), 2) ) ); return distance; } #endregion } }

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176 LIST OF REFERENCES ANSI. (2010). ANSI/GBI Standard. ANSI, < http://www.thegbi.org/greenglobes/ansi gbi standard.asp> (May 30, 2010). ASHRAE. (2010). The Green Standard: Standard 189.1. ASHRAE, < http://www.ashrae.org/publications/page/927> (May 30, 2010). Autodesk. (2005). Building Information Modeling for Sustainable Design. Autodesk, < http://images.autodesk.com/adsk/files/bim_for_sustainable_design_jun05.pdf > (Jan.18, 2009). Autodesk. (2008). BIM and the Autodesk Green Building Studio. Autodesk, < http://images.autodesk.com/adsk/files/bim_and_the_autodesk_green_building_st udio_2008.pdf > (Jan. 18, 2009). Autodesk (2009). Design without compromise. Autodesk, < http://images.autodesk.com/adsk/files/revit_architecture_2010_brochure.pdf > (Jan. 10, 2009). Autodesk. (2009). Revit 2010 API: Developers Guide, Version 1.0 Autodesk, < http://usa.autodesk.com/adsk/servlet/index?siteID=123112and id=2484975> (Nov.18, 2009). Bell, H., and Bjrkhanug, L. (2006). eWor k and eBusiness in Architecture, Engineering and Construction (Martinez, M., and Scherer, R., e ds.), A buildingSMART ontology, 185190, Taylor and Francis, London. Barnes, S., and CastroLacouture, D. (2009). BIM enabled Integrated Optimization Tool for LEED Decisions, Proceedings, International Workshop on Computing in Civil Engineerin g, ASCE, Austin, TX ,258 268. Biswas, T., Wang,T.H., and Krishnamurti, R. (2008). Integrating sustainable building rating systems with bui lding information models, Proceedings 13th International Conference on Computer Aided Architectural Design Research in Asia, CAADRIA, Chiang Mai,Thailand, 193200. CIB. (1999). Agenda 21 on sustainable construct ion, CIB Report Publication 237, Rotterdam, The Netherlands. CRISP. (2002). A European Thematic Network on Constructions and City Related Sustainability Indicators. CRISP < http://crisp.cstb.fr/PDF/CRISP_Final_Report.pdf > (Jan. 10, 2009) Eastman, C., Teicholz, P., Sacks, R., and Liston, K. (2008). BIM Handbook: A Guide to Building Information Modeling for Owners, Managers, Designers, Engineers and Contractors, 1st Ed., Wiley, Hoboken, New Jersey.

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177 Fowler, K.M., and Rauch, E.M. (2006). Sustainable Building Rating Systems Summary, Technical Report PNNL15858, Pacific Northwest National Lab oratory, Department of Energy, USGBC, < https://www.usgbc.org/ShowFile.aspx?DocumentID=1915> (Dec.18, 2008) Gallaher, M.P., OConnor, A.C., Dettbarn, J.L., and Gilday, L.T. (2004). Cost Analysis of Inadequate Interoperability in the U.S. Capital Facilities Industry, National Institute of Standar ds and Technology, Gaithersburg, Maryland. GBCI. (2009). LEED 2009 Minimum Program Requirements. GBCI, < https://www.usgbc.org/ShowFile.aspx?DocumentID=6715> (Jan.18, 2009). GBS. (2009). Autodesk Green Building Studio. Autodesk, < https://www.greenbuildingstudio.com/Account.mvc/Login> (Jan.18, 2009). gbXML. (2009). Open Green Building XML Schema: a Building Information M odeling Solution for Our Green World. < http://www.gbxml.org/> (Jan.18, 2009). Gillard, A., Counsell, J.A.M., and Littlewood, J.R. (2008). The Atlantic College case study exploring the use of BIM for the sustainable design and maintenance of property. < http://www.rics.org/site/download_feed.aspx?fileID=3115andfileExtension=PDF> (Jan.18, 2009). GSA. (2008). 3D 4D Building Informat ion Modeling. GSA, < http://www.gsa.gov/bim > (Dec.18, 2008) Guy, G.B., and Kibert, C.J. (1998). Developing Indicators of Sustainability: U.S. Experience. Proc eeding, t he Second International Conference on Buildings and the Environment (2), Paris, France, 549556. Haagenrud, S.E. (2007). Integration of performance based building standards into business processes using open IFC standards to enhance innovation and sustainable development. EuropeInnova, < http://standards.euinnova.org/Files/Conference/04152008/presentation_StandINN_CEN07.pdf > (Feb.12, 2009). Hkkinen, T. (2007). ISO/TC59/SC17 N 236 Building const ruction/Sustainability in building construction/Sustainability Indicators, WG2 Sustainability Indicators. < http://217.197.210.21/ resources/sustainability/ISO TC059SC17_N0236_Draft_of_New_Work_Item_Proposal__Susta.pdf > (Dec.12, 2008). Haynes, D. (2008). Revit Architecture LEEDing the Way: Additional Materi als. Autodesk, < http://au.autodesk.com/ama/images/media/AB2042 Revit Architecture LEEDing_Additional Materials.pdf > (Jan.18, 2009).

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181 BIOGRAPHICAL SKETCH Wei Wu received his Bachelor of Engineering degree in Built Environment and Equipment Engineering at Hunan University in Chi na in 2004. He proceeded to conduct his masters study in Environmental Change and Management at University of Oxford in the UK, one of the most prestigious universities in the world, and obtained the Master of Science degree in 2005. In 2006 he married Can Liu, an angel he had been dating since thirteen, in London. Also in 2006, he decided to pursue his doctoral degree with a clear interest in the green building and sustainable construction. He was then admitted to M.E. Rinker Sr. School of Building Construction at the University of Florida and awarded a 4year Alumni Fellowship. During his study and research at Rinker, Wei Wu gained substantial academic and industrial experience through teaching, research and internships. Based on his superior academic performance, he was awarded the Certificate of Outstanding Academic Achievement in 2008. The same year, he was recruited by Hawkins Construction, Inc. for a summer internship, during which he obtained comprehensive construction experience. At the end of 2008, he selected his current dissertation topic and literally found his career in the integration of BIM and sustainability. Wei and Can enjoyed the sunshine in Florida. The time at Rinker has been one of the most important stages in their life. Now Wei has fulfilled his academic goals, and he and Can together are ready for any coming adventure.