network contractor, J. Michael Landscape Inc., Marshfield, Mass.; architect, Kallmann McKinnell & Wood Architects, Boston; landscape architect, Pressley Associates Inc., Cambridge, Mass.; and general contractor, Turner Construction Co., Boston
GREEN POINTS: At 15,000 square feet (1394 m2), this extensive green roof is an unirrigated 5-inch- (127-mm-) deep dual-media assembly. Selected for its drought resistance, the profile uses drainage and growth media based on lightweight aggregate. The drainage layer consists of 2 inches (51 mm) of mineral drainage medium. A Leading Edge Wind Stabilization System comprises buried concrete ballasts tethered to a high-strength geogrid to resist winds up to 94 mph (151 km/h). Plant roots knit the three fabrics and two reinforcing layers together. Extensive green-roof areas on the upper podium retain 1 1/2 inches (38 mm) of water and reduce runoff by about 75 percent during warm weather. Other specialized features include stone energy dissipaters and perforated rain conduit.
PROJECT PROVIDED BY ROOFSCAPES INC. / PHILADELPHIA / WWW.ROOFMEADOW.COM