Green Roofs: An Introduction with Pretty Pictures

EcoGeek has a lovely article on Green Roofs.

Green roofs have a layer of living plants on top of the structure and the waterproofing elements.

Green roofs – many advantages, plus they look nice! (if you like green)

There are two types of green roofs:

1. Intensive green roofs have a soil depth of a foot or more, and require substantial structural elements to support the weight of the whole roof. They can sustain a wide range of plant species and typically require a fair amount of regular maintenance.
2. Extensive roofs, much shallower, typically only 2 to 4 inches deep, and are planted with particularly hardy plants.

A green roof can reduce roof stormwater runoff, protect the roof membrane from sunlight (keeps the roofing material from degrading), keep the roof cooler, it’s a source of oxygen and provides a habitat for some birds.

Check the article at EcoGeek for more information.