What is an extensive roof versus an intensive roof?

Extensive green roof: A roof which is covered in low growing vegetation and is usually installed to create advantages from the additional surface protection and maximize ecological benefits. Intensive green roof: A roof which can be covered with large plants, shrubs and trees as well as structures for human activity (walkways, benches, fountains, parking, and so on). They are usually intended to take the form of well-kept gardens. Anything on the ground is possible on the roof given that an adequate load bearing capacity of the building is present. ... more