{Tecta America Corp.} Skokie, Ill., U.S.A.

The Target Center in Minneapolis, Minn., retrofitted the first green roof on an arena and the largest extensive green roof on an existing building in the world. The 2.5-acre project will capture about a million gallons of storm water, preventing its runoff into the nearby Mississippi River. It’s also expected to dramatically reduce the roof’s temperature and alleviate heat island effect in the downtown area. The roof has been planted with a variety of native Minnesota prairie plants, including lupines, which it is hoped will attract the Karner Blue butterfly, an endangered species. Geosynthetic materials are essential in green roof construction, providing a filter fabric, drainage layer, root barrier and waterproof membrane. Visit Tecta America for more information.