Green Roofs
Green roofs are lightweight, engineered rooftops designed to promote the growth of vegetation while protecting the structural integrity of the roof. The technology addresses a wide array of environmental issues associated with urbanization. Environmental and human health benefits of green roofs include air purification, urban heat island amelioration, lower building energy costs, increased urban biodiversity, reduced stormwater runoff and improved stream water quality. And the roofs last longer and are aesthetically pleasing too!
Many of the benefits of green roofs are achieved by the natural capacity of vegetated systems to regulate climate and promote efficient cycling of water and chemicals. Replacing vegetation and trees with dark, heat absorbing building and construction materials in urban areas results in more hot smoggy days and greater energy demand than surrounding natural areas. By putting the vegetation back into the urban environment, green roofs help the natural regulatory functions of the environment to start working again.
The stormwater management benefit provided by green roofs lies in the ability of the soil media and plants to retain stormwater, increase evapotranspiration, and allow stormwater runoff to be released gradually to receiving waters at decreased flow rates. The plants and soil capture pollutants deposited from the atmosphere and eliminate leaching of metals and other pollutants from conventional roof materials.