The use of green roofs refers to a fast-growing (no pun intended) trend toward environmentally friendly building processes. Green roofs are partially or completely covered with vegetation and a growing medium, planted over a waterproof membrane. Some designs incorporate additional layers to form a root barrier and drainage, and even an irrigation system. Think of these as an ultimate rooftop garden oasis.
Long popular in Europe, green rooftops have begun to appeal to homeowners, businesses and even cities as an attractive way to promote environmentalism while solving the problems of conventional roofs. Green roofs supplement traditional vegetation without disrupting urban infrastructure; they take a neglected space and make it useful.1
Green roofs last longer than conventional roofs, reduce energy costs with natural insulation, create peaceful retreats for people and animals, and absorb storm water, potentially lessening the need for complex and expensive drainage systems. On a wider scale, green roofs improve air quality and help reduce the Urban Heat Island Effect, a condition in which city and suburban developments absorb and trap heat. Anyone who has walked across a scalding parking lot on a hot, summer day has felt one effect of an Urban Heat Island.1
Green roofs are commonly referred to as living roofs because they are excellent at absorbing rainwater, providing insulation, creating a habitat for wildlife, and helping to lower air temperatures (especially in an urban location).