US unveils new rating system for sustainable landscaping

A group of organisations today unveiled the US’s first voluntary rating system for the design, construction and maintenance of sustainable landscapes, with or without buildings.

The system was developed by the Sustainable Sites Initiative, a partnership of the American Society of Landscape Architects (ASLA), the Lady Bird Johnson Wildflower Centre and the US Botanic Garden.

“While carbon-neutral performance remains the holy grail for green buildings, sustainable landscapes move beyond a do-no-harm approach,” said Nancy Somerville, executive vice president and CEO of ASLA. “Landscapes sequester carbon, clean the air and water, increase energy efficiency, restore habitats and ultimately give back through significant economic, social and environmental benefits never fully measured until now.”

The rating system works on a 250-point scale, with levels of achievement for obtaining 40, 50, 60 or 80 per cent of available points, recognised with one through four stars, respectively. If prerequisites are met, points are awarded through the 51 credits covering areas such as the use of greenfields, brownfields or greyfields; materials; soils and vegetation; construction and maintenance. These credits can apply to projects ranging from corporate campuses, transportation corridors, public parks and single-family residences.

“We are facing unprecedented environmental challenges such as water scarcity and climate change that require fundamental changes in the way that we interact with the land,” said Susan Rieff, executive director of the Lady Bird Johnson Wildflower Centre at The University of Texas at Austin. “This voluntary rating system and guidelines covers all aspects of working with outdoor spaces of all sizes, and provides information for designing landscapes that go beyond beauty to actually improving ecosystem health and the health of communities for generations to come.”

Added Holly H. Shimizu, executive director of the US Botanic Garden: “Landscapes can give back. We believe that as these guidelines become widely used, not only will they be as transformative to the landscape industry as LEED was to buildings, but more than that, they will allow built landscapes to be regenerative like natural landscapes, and assist in mitigating some of the most pressing environmental issues we face today. We need to acknowledge our landscapes’ value, treasure them and cultivate them sustainably and responsibly. The need is urgent, the time is now and these guidelines, when used correctly, are the tools.”

To test the rating system, the Sustainable Sites Initiative has opened a call for pilot projects. Any type of designed landscape is eligible, so long as the project size is at least 2,000 square feet. The call will remain open until 15 February, 2010, and the initiative will work with and oversee the projects during the two-year process.