When D.C. area businesses and institutions decide it’s time for a new roof, more are making the decision to go green.
The District is second only to Chicago in the square footage devoted to green roofs, according to an annual survey by Green Roofs for Healthy Cities, a Toronto-based industry association. Dulles ranked fourth on the list.
Buildings with green roofs are partially or completely covered with vegetation and soil, which gets planted over a waterproofing layer. The roofs are designed to save energy costs, reduce stormwater run-off and improve air quality.
Green roofs are a trend on the rise, showing more than 25 percent growth during 2006, Steven Peck, the association’s founder, told The Examiner.
Green roofs can be found in the D.C. area atop government buildings such as the U.S. Department of the Interior, educational institutions like the Sidwell Friends School and housing projects like Eastern Village in Silver Spring.
D.C.’s 32 green roof projects cover 301,751 square feet. Dulles’ high ranking was the result of one large-scale project: the 230,000-square-foot green roof at Howard Hughes Medical Institute’s research campus.
The D.C.-based American Society of Landscape Architects finished its own project last April. The group hopes the new roof, which has been retaining 77 percent of all rainfall since its construction, will become a demonstration project that encourages others to follow suit, Executive Vice President Nancy Somerville said Friday.
The structures are generally more costly than ordinary roofs — costing $15 to $20 per square foot rather than $8 to $14 per square foot for conventional roofs, Somerville said. The architect group invested more than $900,000 in its own project, though most of those costs were for a stairwell extension that made the roof accessible, she said.
