Green roofs, also known as living or vegetated roofs, consist of plants and specialized soil over a protective, waterproof membrane that is laid on top of an existing roof structure. The plant palette is comprised of species that are able to tolerate high heat and dry conditions, such as native glade species and non-native plants such as Sedum or creeping thyme.
A green roof captures, slows down and reduces the quantity of rainfall before it enters the gutter. Green roofs also add energy savings by insulating the roof thus reducing heating and cooling costs. The existing roof must be reinforced to carry the additional weight load, anywhere from 15–30 lbs./sq. ft. or more depending on the depth of the soil. While installation of a green roof is initially more expensive than a conventional roof, a green roof has a much longer life span than a conventional roof. Approximate costs may range from $15/sq. ft. to $25/sq. ft. or more depending on the depth of the green roof soil and the specific plants used in the planting. When considering installing a green roof, it is recommended that you consult with an engineer/architect and a reputable roofing company well-versed in installing green roofs.
See our Green Roof Resources section for more information.