April 21, 2006—The area of US roofs covered by vegetation has increased more than 80 percent in the past year, according to Green Roofs for Healthy Cities (GRHC), a trade association.
Green roofs are rooftop gardens that reduce storm water runoff; insulate against heat and sound; increase energy savings; and improve air quality. They also reduce the urban heat island effect, which is caused by dark urban roofs, pavement, and other infrastructure absorbing the sun’s heat.
The GRHC recently completed its first survey of its members to gauge the growth of green roofs, finding that in 2005, green roofs covered at least 2.5 million square feet of roof space in North America, up from 1.3 million square feet in 2004.
Cities that incorporate the largest area of green roofs in 2005 include Chicago, Illinois; Washington, D.C.; and Suitland, Maryland. Toronto may catch up to these other cities quickly, since the city council recently passed a policy that requires green roofs to be incorporated into city buildings and provides financial incentives for green roofs.
For more on green roofs, visit the GRHC Web site.
