Environmentally responsible building methods such as vegetative roof systems and LEED®-certified construction practices continue to increase in popularity as sustainable buildings and designs prove to be environmentally and financially beneficial. Municipalities throughout the U.S. are following the example of cities such as Chicago, which currently leads the nation in vegetative roof systems. Local governments are offering tax incentives for homes and businesses to go green and, in some cases, mandating certain building practices for new construction.
Made more accessible by advances in water, horticulture and engineering sciences, vegetative roof systems' popularity in the U.S. is increasing after many successful years in Europe, primarily in Germany. Vegetative roof systems offer many long-term benefits when installed correctly.
The NRCA Vegetative Roof Systems Manual, Second Edition defines a vegetative roof system as "a roof area of plantings/landscaping installed above a waterproofed substrate at any building level that is separated from the ground beneath it by a man-made structure. A vegetative roof system consists of a waterproofing system and its associated components—such as protection course, root barrier, drainage layer, thermal insulation and aeration layer—and an overburden of growth medium and plantings."