Originally posted Tuesday, 16 April 2013
Written by Chris Towery
Today, with widespread support for sustainability in the construction industry, much progress has been made in improving the environmental efficiency of buildings. So far, however, there’s been comparatively minimal focus on enhancing the sustainability of the built landscapes and natural ecosystems that surround these buildings. The Sustainable Sites Initiative (SITES) was launched to fill that void, and after nearly eight years, the initiative is making major progress in fulfilling its mission.
SITES seeks to promote sustainable land development and management practices that can apply to sites both with and without buildings. To this end, the initiative seeks to establish voluntary national guidelines and a rating system to measure performance of a site or landscape project, from pre-design site assessment all the way through design, site preparation, construction, and into operations and maintenance. Ultimately, SITES aims to provide helpful tools for all of those involved with designing, constructing, and maintaining built landscapes, including Owners of capital construction projects.
Although the well-known LEED sustainable ratings system includes some guidelines for the sustainability of built landscapes, many ecologists believe that LEED fails to adequately address this area. According to Nancy Solomon’s article “Site Specific” in the July 2012 issue of Architectural Record, proponents of SITES argue that LEED’s “requirements and recommendations for landscape strategies barely scratch the surface of what should be done to reverse the devastation that decades of poor design, construction, and maintenance practices have wrought on vital natural ecosystems.”
This lack of attention from LEED was the impetus for the first Sustainable Sites Summit in 2005 at the University of Texas in Austin. At the summit, members from the Sustainable Design and Development Professional Practice Network of the American Society of Landscape Architects (ASLA) and the Lady Bird Johnson Wildflower Center gathered to address the issue and ultimately founded SITES. The United States Botanic Garden joined these two groups as a major partner in 2006, and since then, 11 other organizations, including the U.S. Environmental Protection Agency, the Nature Conservancy, and the US Green Building Council, have joined SITES as stakeholders to provide the initiative with further direction and guidance. According to the SITES website, the final version of SITES will be organized in a LEED-like format, and the USGBC eventually plans to incorporate SITES into future iterations of LEED.
In 2007, SITES released the supporting document The Case for Sustainable Landscapes, which laid out the reasoning and principles behind the initiative. The underlying principle of SITES is that healthy landscapes provide a number of valuable benefits, known as “ecosystem services,” which form the very foundation of a healthy ecosystem but are often overlooked by developers. These services include such things as flood protection provided by wetlands; pollination of crops by insects, bats, and birds; and the filtration of pollutants from the air and water by healthy vegetation and soil. SITES found that current land-use practices have negatively affected many essential environmental functions, such as air purification, climate regulation, water retention, and erosion control. By adopting sustainable practices that restore and enhance these ecosystem services, SITES aims to not only protect and restore the natural environment, but also to enhance human health and well-being.
SITES also aims to make landscape sustainability cost effective. Since the benefits of healthy landscapes are difficult to calculate, their economic value is often overlooked. According to The Case for Sustainable Landscapes, “Ecosystem services provide benefits to humankind and other organisms, but are not generally reflected in our current economic accounting. Nature doesn’t submit an invoice for them, so humans often underestimate or ignore their value when making land-use decisions. However, efforts to determine the monetary value of ecosystem services have placed that figure at an estimated global average of $33 trillion annually (in 1997 dollars).”
To develop the best practices for enhancing landscape sustainability, SITES gathered more than 50 experts in five technical subcommittees: soils, hydrology, vegetation, human health and well-being, and materials selection. These experts worked to create a set of benchmarks for sustainability that can be applied to any type of site in any bioregion. In 2009, SITES released a preliminary version of this rating system, known as Guidelines and Performance Benchmarks 2009. These preliminary guidelines are divided into nine categories, including site selection, pre-design assessment and planning, water, soil and vegetation, materials selection, human health and well-being, construction, operations and maintenance, as well as monitoring and innovation. Across these nine categories, the guidelines feature 15 prerequisites and 51 credits that apply toward final SITES certification, which uses a four-star rating system based on a 250-point scale.
To participate in SITES, a project must first meet all 15 prerequisites, which include such actions as protecting floodplain functions, restoring soils disturbed during construction, and providing for sustainable site maintenance. From there, a project earns point-generating credits by choosing from a wide range of sustainability practices. While these practices are optional, a certain number of them must be attained to achieve certification. For example, by recycling organic matter generated by site operations and maintenance, a project can earn up to 6 points, and by selecting a brownfield for redevelopment, a project can earn 10 points. With a maximum of 250 points available, projects that earn at least 100 points are awarded one-star SITES certification, those that earn 125 are given two stars, those that earn 150 points are given three stars, and four stars are given for 200 points or more.
In June 2010, SITES launched a two-year Pilot Program to test and revise the Guidelines and Performance Benchmarks 2009. The Pilot Program concluded in June 2012, with more than 155 pilot projects in 34 states having participated. Feedback from the Pilot Program is currently being analyzed to come up with a final rating system and develop the technical manual SITES Reference Guide. The Reference Guide, which will replace the Guidelines and Performance Benchmarks 2009, is slated for release in fall 2013. In addition to a revised ratings system, it will also feature credit examples, worksheets, documentation criteria, calculation guidelines, and an improved user experience.
Since the Pilot Program launched, a total of 15 pilot projects have achieved SITES certification. Of the 15 pilot projects that have been awarded certification, three involved landscape development on university campuses, making them particularly valuable examples for the ways in which other Owners can adopt SITES practices. These three projects include Cornell University’s Mann Library Entrance, Grand Valley State University Student Recreation Fields, and The Green at College Park at The University of Texas at Arlington. The Green at College Park is a particularly notable project, as it was built to interact with the University’s new College Park Center, which won a 2012 COAA Project Leadership Gold Award and is profiled in this issue on page 6. Details of the SITES practices employed at The Green are listed below.
The Green at College Park at The University of Texas at Arlington
Certified in January 2012, The Green at College Park was one of the first three projects to become SITES certified. The location was previously a large parking lot that suffered from poor drainage and frequently flooded a nearby creek during heavy rains. With the new development, The Green is now a beautiful 2.6-acre park on the south side of the University’s new College Park Center, a 7,000 seat special-events arena. The Green includes a gathering plaza, activity lawn, pedestrian promenade, shade arbors, layers of seating and other pedestrian amenities. Ecologically, the site predominately functions as a water detention system and large-scale rain garden.
The Green was specifically designed to interact with and enhance the sustainability of the new College Park Center, which was awarded LEED Gold certification in April 2012. Specialized soil, plants, and design features in the park will provide for a more than 25-percent decrease in the amount of storm water runoff that would have been expected from the 218,000-square-foot arena. Some of the most prominent SITES strategies The Green incorporates include:
Storm Water Treatment and Detention: An existing eroded drainage rill on the site, which flowed into the already-overwhelmed Johnson Creek, spurred the concept of turning drainage into a major site feature and amenity. The site’s storm-water detention slows, cleans, and detains every drop of rainwater and vastly increases the on-site infiltration rate. Additionally, a “storm spring” allows water in underground storm drains from other areas of the campus to enter the site during large storm events to be filtered and retained.
Minimal Potable Water Use: The plants in the drainage gardens thrive in both drought and flood conditions, and they also provide valuable habitat to the site, which was once paved from curb to curb. This planting palette keeps potable water consumption to a minimum. A drought-tolerant and low-mow lawn has been limited to the recreational area, and all other sections are planted with large masses of prairie grass.
Sustainable Materials Selections: Shade and paving selections minimize the heat island effect in the spaces designed for gatherings and activity. The materials used are primarily from the region or come from recycled sources. The rill garden features the first North Texas installation of a pervious paving material made from recycled glass, mixed with a small amount of polymer and crushed granite, called Filter Pave.
Educational Signage: Interpretive signage educates the public about the environmental ethic of the project and the complex natural systems that have been returned to a once-degraded site.
Once the final SITES ratings system is released this fall, SITES will launch its official open enrollment, so 2013 is shaping up to be a landmark year for the initiative. Around 80 of the 155 pilot projects not yet certified have declared that they will continue to seek SITES certification, and four new projects became certified as recently as March. Moreover, the initiative has even received recognition from the White House.
Last October, the White House Council on Environmental Quality used the SITES preliminary guidleines to develop the Guidance for Federal Agencies on Sustainable Practices for Designed Landscapes, which helps federal agencies meet sustainability goals. The document points to SITES practices as a way for agencies to create more sustainable landscapes by focusing on ecological elements, such as healthy soil, native vegetation, and improved hydrology. With this attention from the federal government, several cities and businesses across the country are also looking for ways to adopt SITES. In the end, the hope is that SITES will eventually transform the design, construction, and maintenance of sustainable landscapes in the same way LEED has affected sustainable buildings. And with the progress that has been made thus far, that goal may not be too far off.
For more information on SITES or to submit your project for certification, visit www.sustainablesites.org