Diagram of a green roof application (taken from the Low Impact Development Center website).
Green roofs, also known as "living roofs", consist of vegetation or soil planted over a waterproofing membrane and offer many aesthetic, economic and environmental benefits. Environmentally, they have the ability to provide temperature and acoustic insulation which increases energy efficiency and reduces the urban heat island effect, provide biodiversity preservation, improve air quality, and retain and cleanse storm water.
Typical green roof systems consist of the following layers: vegetation, a growing medium, the landscape (to contain the growing medium while allowing water penetration), a specialized drainage layer, waterproofing/roofing membrane, and the roof structure with the traditional insulation above or below.
