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A Comparative Analysis of the Capital and Maintenance Costs of Sustainable and Conventional Landscape Design

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Title:
A Comparative Analysis of the Capital and Maintenance Costs of Sustainable and Conventional Landscape Design
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Lewis, Gary
Acomb, Glenn ( Mentor )
Place of Publication:
Gainesville, Fla.
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University of Florida
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English

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University of Florida
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University of Florida
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A Comparative Analysis of the Capital and Maintenance Costs of
Sustainable and Conventional Landscape Design

Gary Levis


ABSTRACT


In sustainable residential development, the existing ecosystem, conservation of resources, and ease of

maintenance are given a priority. The process includes minimal clearing, retaining as many native plants as

possible. The cleared area is replanted with primarily native, drought-tolerant plants requiring a minimum of

pruning, pesticides, fertilizers, and water. Mulch is used as a ground cover wherever possible. Turf grasses,

which require high maintenance, water, fertilization, and pesticide treatments, are used sparingly. Stormwater

runoff is controlled and allowed to percolate back into the ground.



Conventional residential development, on the other hand, tends to be subject more to the ease and economy

of building and to immediate curb appeal than to the ultimate well-being of the existing ecosystem, conservation

of resources, or the ease of maintenance. Typically, building lots are cleared of most of the vegetation and

replanted predominantly in turf and a few eye-catching ornamental shrubs, which may or may not be native

species and easy to maintain. Stormwater is allowed to run off into storm drains.



In the analysis of these two systems, comparing two identical building lots, one developed conventionally, the

other in a sustainable manner, we hope to show that in the long run it is both cost-effective and

environmentally beneficial to design with sustainability in mind. We will compare initial installation costs as well

as maintenance costs, incorporating environmental impacts wherever possible.



INTRODUCTION


The May 27, 2004 issue of Miami Today reported that, according to the U. S. Census Bureau, more housing

permits were issued in Florida in March 2004 than in any other state, up 33% from the previous year. With

this tremendous increase in construction comes an inevitable impact on the environment. It is paramount that

this impact be evaluated so as to minimize its harmful effects and preserve the environment and its resources

for future generations.



Sustainability has been defined as "meeting the needs of today's population without diminishing the ability of

future populations to meet their needs." It has been compared to the Great Law of the Iroquois Confederation,





which suggests that decisions should consider the effect they will have on the next seven generations (Thompson

& Sorvig, 2000). Sustainability can be implemented from the smallest to the largest scale. For the scope of

this project sustainability involves the efficient use of resources in the planning, design, and construction of

a particular site. Furthermore, it assumes the continued efficiency in the operation and management of the

site. Ultimately, the desire would be that the scope would not be merely site-oriented, but extend to the

larger community, affecting various aspects of the universal quality of life.



Typical conventional methods of construction do little to encourage an attitude of sustainability. From the

viewpoint of a developer or contractor, the motivational factors are based on the desire to achieve the most

attractive landscape at the lowest cost. In conjunction with this is the desire for the project to reach completion

and be sold as soon as possible in order to minimize interest payments as well as enhance cash flow. It is often

most economical both temporally and financially to clear the majority of the existing vegetation from a building site

in order to allow for the ease of movement and access into the site by the subsequent trades people. Only

the largest, most aesthetically appealing trees are left undisturbed. Hardscapes such as driveways, walkways,

and patios are constructed from impervious materials, such as concrete, that do not allow stormwater to

naturally nourish the landscape and to percolate back into the ground. Instead the runoff typically flows

offsite, where it is collected via storm drains into large detention ponds. The subsequent landowner is then

required to satisfy the watering needs of the landscape by means of an irrigation system.



Following the completion of the building construction, the resulting landscape is planted in order to achieve

maximum street appeal to attract potential buyers onto the property. The choice of plants is, once again, based

on financial constraints, but also on the assumed tastes of the potential buyer. Foundation plants consist of

any number of evergreen, often glossy-leafed, shrubs. Perhaps there is an island somewhere in the front yard

with some eye-catching shrubs, and, maybe, a few specimen trees. These plants may or may not be

sustainable, requiring varying amounts of fertilization, watering, and pesticides. But the majority of the yard

is planted in turf grass. Not only does turf grass require large amounts of fertilization, water, and pesticides, but

also it requires an intensive maintenance schedule, including mowing, raking, and aerating.



The above process can apply to any area in the United States, with each being impacted in general but also in

a localized, specific way. The need to conserve water is a prime example. That water is a valuable commodity is

a generally assumed fact, and in Florida the need for clean water is a critical issue. From 1960 until the year

2000, the population of the state increased by 300% from less than 5 million to more than 15 million

(Purdum, 2002). With this increase came what has been called the Florida Water Wars, which resulted in hundreds

of millions of dollars in lawsuits, not to mention the environmental damage (Pittman & Hauserman, 2003). It

has been estimated that between 30 and 60% of urban water use in the United States is used in watering

lawns covering 31 million acres (Bormann, Balmori, & Geballe, 2001). To allow rain to fall only to drain down a

storm sewer rather than to be used for landscape irrigation on site is not only less than wise but also wasteful

and expensive.





The cost of maintaining lawns in the United States is $30 billion annually. In addition to the cost are the side

effects of this maintenance. An estimated 60% of the nitrogen applied to lawns as fertilizer is leached into

the groundwater as nitrate. Nitrate in drinking water may cause birth defects, cancer, and nervous

system impairments (Bormann, et al., 2001). Nitrogen gas are also a major contributor to the greenhouse effect.



Lawn mowing not only depletes fossil fuels, but also emits pollutants and greenhouse gases. According to

the California Air Resources Board, the burning of the fuel needed to mow one lawn produces emissions equivalent

to driving 350 miles. Annually, California lawn maintenance contributes pollutants equal to 3.5 million

1991 automobiles driven 16,000 miles each (Bormann, et al., 2001).



The ultimate problem with this scenario is that the environment is impacted in several harmful ways. Air and

water pollution, resource depletion, and the destruction of wildlife habitats are merely broad descriptions

that encompass a multitude of specific problems exacerbated on a daily basis by society's desire to achieve what

is the accepted standard of an attractive yard. Ironically, these same homeowners drive on weekends to

undisturbed natural areas to absorb nature and marvel in its beauty. In time, the accepted residential

landscaping aesthetic, as with any fashion sense, may be influenced and altered, but an understanding of the

positive environmental impacts and financial benefits of sustainable design will hopefully act as a catalyst for change.



METHODS



A comparative analysis was done comparing the cost of developing and maintaining an existing sustainable

landscape with an imagined conventional design on the same lot. The property used for the comparison is the

model home located south of the University of Florida campus, Gainesville, Florida, in a developing subdivision

named Madera. The home is built on a _ acre lot that was developed with sustainable ideals in mind.

The conventional plan involves the same lot as if it was developed in a conventional manner. The total cost

of construction was manipulated to the extent that the amount spent on landscaping plants is identical in

both scenarios.



The costs of installation include clearing, planting, mulching, sod laying, driveway installation, and irrigation

system installation. In addition, the annual maintenance costs were compared. These included lawn care, such

as mowing, fertilization, trimming, pesticide application, and leaf blowing. A detailed explanation of each item

is delineated (Table 1).



Table 1
Sustainable and Conventional Design Cost Comparison

Sustainable Design Conventional Design

Costs Quantity Cost Quantity Cost

Capital Costs








Mulch (unplanted beds) 1296 sq. ft. $233.28 505 sq. ft. $90.90

Mulch (planted beds) 1940 sq. ft. $349.20 359 sq. ft. $64.62

Plant installation $8,247.00 $8,247.00

Turf 1600 sq. ft. $720.00 5180 sq. ft. $2,331.00

Natural Undisturbed 1216 sq. ft. 0 sq. ft.

Driveway 1896 sq. ft. $11,376.00 1896 sq. ft. $7,584.00

Irrigation System $900.00 $1,500.00

Total 7940 sq. ft. $23,014.48 7940 sq. ft. $21,048.52



Annual Operating and Maintenance Costs (for year 2004)

Maintenance (42 visits) $1,470.00 $3,150.00

Pesticide Treatment (5 $200.00 $300.00
visits)

Watering 41,602 gals. $51.84 134,120 gals $167.51

Total $1,721.84 $3,617.51

After 5 years $8,609.20 $18,087.55

After 10 years $17,218.40 $36,175.10

Notes:
Capital Costs:
Clearing/Grading. The amount is based on a cost per acre of $2,415 to remove trees with a
bulldozer with an additional $.48 per square yard for grading (Spencer, 2003).
Mulch and Mulch with Ornamentals. Although these two areas are separated in order to
designate the specific size of each, they are both treated in a similar manner by spreading
a 2" layer of wood mulch over the soil at a cost of $35 per cubic yard. The first bed is then
left as-is, while the second is planted with ornamental shrubs or trees. The cost of the
planting is treated separately. (Estimate based on conversation with Landscaping
Contractor Rex Glover, owner of Sunshine Greenery, Micanopy, FL.)
Turf. This amount is based on a cost of $.45 per square foot and includes amending the
soil, hand grading, and laying St. Augustine sod. (Estimate based on conversation with
Landscaping Contractor Rex Glover, owner of Sunshine Greenery, Micanopy, FL.)
Natural Undisturbed. This refers to areas in the sustainable design that are left totally
undisturbed ,requiring no capital or maintenance expenses.
Driveway. The sustainable design incorporates using permeable pavers that allow water to
penetrate and percolate back into the ground at a cost of $6 per square foot. The
conventional design uses a typical concrete slab at a cost of $4 per square foot. (Estimate
based on conversation with General Contractor Paul Emery, owner of Emery Construction,
Gainesville, FL.) This cost comparison is possibly deceiving, in that the sustainable plan
promotes the concept of shared driveways between adjacent lots, thus reducing the cost
per lot significantly.
Irrigation System. Only the areas of turf and ornamental plantings would require irrigation.
The mulched and natural areas in the sustainable design would not. (Estimate based on
conversation with Landscaping Contractor Rex Glover, owner of Sunshine Greenery,
Micanopy, FL.)

Annual Operating and Maintenance Costs:
Maintenance. The services provided in this category include lawn mowing, edging,
fertilizing, and trimming, occurring 42 times annually and performed by a landscape
maintenance contractor .(Estimate based on conversation with Landscaping Contractor


Clearing/ grading


$1,189.00


$1,231.00





Rex Glover, owner of Sunshine Greenery, Micanopy, FL.)
Pesticide Treatment. This service provides lawn pesticide treatments 5 times annually by a
landscape maintenance contractor. (Estimate based on conversation with Landscaping
Contractor Rex Glover, owner of Sunshine Greenery, Micanopy, FL.)
Watering. This amount is based on the assumption that the lawn is irrigated with 1/2" of
water twice weekly in the summer months (April - October) and once weekly in the winter
(November - March). The summer water rate is figured at $1.33 per gallon; the winter rate
is $1.01 (Gainesville Regional Utilities, 2003).



RESULTS AND DISCUSSION



The difference between the two installation costs was estimated as less than $2,000, with the sustainable

design being the higher. In the areas that included mulch, plants, and grass, the conventional design costs were

only slightly more than the costs of the sustainable design. But the driveway of the sustainable design cost

50% more than the conventional; however, the irrigation system for the conventional design cost 66% more than

the sustainable. Although the landscaped area in the sustainable design had much less area of turf, the areas

without turf were designated to be covered with a layer of mulch. So, although the turf area in the sustainable

design was only a third of the area of the conventional design, and therefore a third of the cost, the cost of

mulch installation in the sustainable was four times the cost of the conventional.



The driveway in the sustainable design has been specified to be constructed from permeable pavers, as opposed

to the poured concrete of the conventional design. The cost of the pavers was the one item that resulted in

the sustainable design being the more expensive of the two, with the cost of the pavers being nearly $4,000

more than poured concrete.



The real comparison is in the long-term maintenance costs of the two designs. The cost of annual maintenance of

the conventional landscape is more than twice the cost of the sustainable, bringing to total cost of the two within

less than $100 in the first year. The conventional would easily surpass the sustainable in total cost in the

second year. In ten years the total cost of the sustainable landscape would be more than $17,000 less than

the conventional landscape: $40,000 as compared to $57,000.



CONCLUSION



An understanding of the ecological advantages, coupled with the knowledge of potential financial savings

connected with sustainable landscaping, should encourage trends in that direction. What is worth pointing out is

that this is not an all-or-nothing proposition. Not only can sustainability be advanced to whatever degree a

developer or homeowner feels comfortable with, but it can begin at whatever stage of maturity a landscape

happens to be.



Minimal clearing, avoiding soil compaction, and protecting large trees are basic means to maintaining a healthy

site from the onset (Thompson & Sorvig, 2000). Developers should keep as much of the existing vegetation as





is possible, supplementing it with native vegetation, or at least with vegetation suited for the environment,

rather than choices requiring additional water, nutrients, or chemical additives. The amount of turf should be

limited by using other groundcovers or mulches where shrubs or trees are not suitable. Impervious surfaces,

which allow the rain that falls on the site to remain should be used.



The maintenance of a landscape should be approached with an attitude of restraint and conservation.

Homeowners should water less and only when necessary; they should also fertilize less, realizing that a

healthy ecosystem provides its own, and use pesticides and herbicides sparingly, if at all. They should mow

less, allowing the clippings to remain on the lawn to decay and provide nutrients. Then homeowners will have

the satisfaction of knowing that, not only has a future healthy environment been promoted, but also that money

has been saved in the bargain.






REFERENCES


1. Bormann, H. F., Balmori, D., & Geballe, G. (2001). Redesigning the American Lawn: A Search for

Environmental Harmony. New Haven: Yale University Press.

2. Bowden, M. (2004, May 27). Land shortages threaten South Florida home construction. Miami Today.

Available: http://www.miamitodaynews.com/news/040527/story3.shtml.

3. Gainesville Regional Utilities. (2003). Residential Rates: Electric, Gas, Water, & Wastewater. Available: http://

www.gru.com/Pdf/RatesCharges.pdf.

4. Pittman, C., & Hauserman, J. (2003, August 10). North has it, South wants it. St. Petersburg Times. Available:

http://www.sptimes.com/2003/08/10/State/North has it South_w.shtml.

5. Purdum, E. D. (2002). Florida Waters: A Water Resources Manual from Florida's Water Management

Districts. Available: http://www.sjrwmd.com/programs/outreach/pubs/index.html.

6. Spencer, E. R. (Ed.) (2003). Sitework and Landscape Cost Data. Kingston, MA: RSMeans Construction Publishers

and Consultants.

7. 'Thompson, W., & Sorvig, K. (2000). Sustainable Landscape Design: A Guide to Green Building Outdoors.

Washington DC: Island Press.



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