What is a green roof?

A green roof (vegetable roof or vegetalized roof) is a roof made with a covering of topsoil on which plants are grown.

By absorbing heat, green roofs reduce the amount of cooling needed by buildings as well as filtering pollutants and C02 out of the air. During strong rains, cities have often had to evacuate water. A sufficient surface of green roofing increases the absorption of rainwater, which would in turn, relieve the sewer system. Green roofs also offer a good soundproofing as well as an oasis of greenery.

Diagram of an extensive green roof system with insulation: