A green roof is a roof on a building that is partially or completely covered with vegetation and soil or a growing medium, which is planted over a waterproofing membrane.
Green roofs are used for stormwater management and energy savings, as well as for aesthetic benefits. Green roofs absorb stormwater and release it back into the atmosphere through evaporation and plant transpiration, while reducing urban temperatures by limiting the amount of heat retaining structures. The vegetation on the roofs also absorbs a great deal of the pollutants in the water before it is released into the atmosphere. Green roofs can also help create habitats for local butterfly, insect, and bird species.