Green/living roof
A roof surface covered by a waterproofing membrane, a drainage plane, a water-retention medium, and plantings of drought-resistant species. The benefits of a green roof include control of stormwater runoff, which can reduce urban water pollution; absorption of airborne toxins and an increase in oxygen in the air; and a reduction of surface temperature of the roof, called the heat island effect. A living roof can also increase the lifespan of the roof system and provide building and noise insulation. Green roofs are most common in multifamily or other large urban buildings.
Illustrated Dictionary of Architecture Copyright © 2012, 2002, 1998 by The McGraw-Hill Companies, Inc. All rights reserved