What is a Green Roof?

• A green roof is a roof that has been covered with living vegetation that will provide stormwater management and other benefits.

• A green roof can be added to an existing roof, and can cover all or part of the roof.

• A green roof is typically a “passive” space—where plants are growing but human access is limited to installation and maintenance. A vegetated roof that is intended as a space for people to utilize is called a “roof garden.” Both have stormwater benefits, but green roofs typically provide greater stormwater retention.

Why Develop a Green Roof?

• Green roofs provide a lush oasis in the city, helping to reduce the “urban heat island” effect, produce fresh oxygen, serve as a natural habitat and reduce heating and cooling costs for a building by acting as an additional layer of roof insulation.

• Green roofs retain stormwater and reduce the flow of stormwater during a rain event.

• Green roofs help to filter pollutants from the excess stormwater that runs off of the roof.