Vegetation on the roof of a building increases the insulation capacity factor of the roof. Firstly the vegetation ensures thermal insulation in the winter. Furthermore the vegetation prevents direct sunlight on the roof making the building cooler in the summer.
Particulates and rainwater
The vegetation on the roof binds particulates and can buffer up to 50% of the run-off water. This relieves sewers during heavy rainfall.
Grey water can, in combination with a green façade, be collected, filtered and reused in the flushing system in the building.
Besides supporting habitats within the city, green roofs also have an aesthetic quality. This increases the natural look in an urban environment.
Because of the benefits more and more cities grant significant subsidies to stimulate vegetation roofs.