Keyword Site Search

Rating Green Parking

By Buck Abbey, ASLA, Robert Reich School of Landscape Architecture, Louisiana State University

The author designed this parking lot with SITES standards in mind. The green elements for this parking lot and their associated SITES rating system points include a stormwater retention area with a 90 percent improvement in runoff capacity (10 pts.); eco-vehicle parking (4 pts.); preserving a specimen oak (5 pts.); salvaging plants from construction site (4 pts.); riparian buffer (8 pts.); soil disturbance minimized (6 pts.); shade trees and reduced use of paving to lower heat island effect (5 pts.); native plants used to shade/screen parking (4 pts.); native plant community restored (6 pts.); stormwater bioswale as landscape feature (3 pts.); pavers made from regional materials (6 pts.); seating area (3 pts.); parking lamps with cutoff shades (2 pts.) The parking lot earns 167 points (a "three-star" rating) out of a possible 250 points.
Source: A Green Parking Lot Rated for Green. J. Sellers, Abbey Associates, Inc.
Steve - ASLA AD
Cost of Wisconsin
teak USA Vinyl
Architectural Iron Custom Canopies

The Sustainable Sites Initiative (SITES) provides guidelines and performance benchmarks to measure site sustainability. This innovative program, a collaboration between the ASLA, the U.S. Botanic Garden and the Lady Bird Johnson Wildflower Center at the University of Texas, offers assistance to landscape architects interested in more sensitive site design based upon sustainable practices.

These practices are known to reduce energy usage, make sites healthier and conserve or protect scarce natural resources. This is the essence of sustainable site design.

In LEED-type fashion, the SITES rating system is based on levels of effectiveness. This system is designed to measure the value of ecosystem services in a way that points or ''stars'' can be provided by meeting benchmarks either in planning, design or construction. Up to 250 points from 51 credit categories can be earned on a four-star scale.

One Star - 100 points (40%)
Two Star - 125 points (50%)
Three Star - 150 points (60%)
Four Star - 250 points (100%)

These rating Stars are earned by meeting ''specific standards'' found on rating sheets that cover such design issues as ''site selection, pre-design assessment and planning, water, soil and vegetation, site, materials selection, human Health and well being, construction, operations & maintenance, monitoring and innovation.''

Rating sheets have been prepared to cover each of these specific standards. Points are awarded for meeting both ''prerequisites, and credits.'' The prerequisites are required, but the credits are optional. No points are earned for prerequisites and one or more points can be earned for the credits. The rating sheets are easy to understand and easy to use.

''Areas that are considered to be of high ecological importance should be given
highest priority for protection.''

-Florida-Friendly Model Landscape Code, 2009

Rating Green Parking
Can SITES measure the sustainability of green parking lot design? Yes it can. It's a very useful tool, but one must review all benchmarks in the ratings and select the salient factors for parking lot design. The author did so using the Guidelines and Performance Benchmarks 2009 and identified 184 points. As noted, 100 points earns a one star rating. It would be a great step forward for urban parking lot design if all community landscape codes set a minimum rating of one star for parking facilities.

Many basic sustainability principles are included in the rating sheets. The most important include reducing the use of potable water, harvesting and managing storm water, protecting wetlands and preserving vegetation. Others include the use of native plants, preserving building energy, reusing salvaged materials, designing with regional materials and providing opportunities for outdoor physical activities. Points can also be earned for reducing the use of outdoor energy in parking lots and making parking lots tobacco free zones.

This layout shows plans for a green parking lot bioswale and shade plan. This parking lot design features storm water management, appropriate planting, shading, screening, energy reduction and minimizing irrigation needs.
Source: W.Tieje, Abbey Associates, Inc.

Calculating Green
Using the SITES rating sheets, it is possible to design complete project site or something as small as a parking lot, playground or garden.

One way to determine if a parking lot has been designed green is to do the calculations required to see how it measures sustainability. Fig. 1illustrates a parking lot designed by the author to meet SITES standards. The plan shows several common greening solutions under SITES. Paving, stormwater, climate modification, use of plants and construction materials and preservation of habitat and improvements to human well being have all been included in the design. The parking lot design in Fig. 2 features storm water management, appropriate planting, shading, screening, energy reduction and minimization of the use of potable water supplies. A few landscape best management practices, such as mulching, lawn grass reduction, composting in place, bed construction and yard chemical control, have been included in the design even though not measured by SITES.

Each category in SSI comes with a rating sheet to measure sustainability outcomes. Rating sheets offer options to gain points. Points are awarded based upon the intensity of meeting the benchmark. Multiple point values represent incremental improvement toward fully achieving the intent of the rating credit.

Intensity is typically determined from tables, formulas, percentages, area, linear footage, volume or some quantifiable industry standard. Some ratings vary by geographic regions, e.g., more points are earned for the use of harvested rainwater in the arid Southwest than in the humid South. The biomass density index values of Southeast forests exceed Southwest grasslands by a factor of four.

The value of SITES is the rating sheets quantify sustainability with numbers. ''If you can calculate points, it sells,'' notes one landscape architect.

The Fig. 1 plan rated 167 points, a three-star rating. In the calculation of the illustration, assumptions have been made in regard to operation, maintenance and monitoring. Technical construction details and specifications were not developed, although SITES will require them as a significant part of certifying the project.

After testing the ASLA SITES method one has to wonder why landscape architects are not designing all parking lots to meet sustainability standards? It is good for the environment, challenging to the designer and greens the city.

Related Stories

November 22, 2019, 1:22 pm PDT

Website problems, report a bug.
Copyright © 2019 Landscape Communications Inc.
Privacy Policy