To start with take a look at the most simple family of green roofs.
Intensive green roof definition.
Intensive green roofs require the deepest soil and have the greatest impact on the structural design but they also accommodate all types of plantings including large shrubs and trees.
The intensive green roof uses planting mediums that have greater depth than the extensive green roof.
Intensive green roof plants require the deepest soil but also have the greatest impact on structural design.
The depth of an intensive green roof ranges from 15 cm to as much as 150 cm and can easily weigh as much 300 to more than 1500 kg m2.
Extensive green roofs are lightweight with a shallow layer of growing substrate of less than 200 mm deep requiring minimal maintenance.
This deeper soil allows intensive roofs to accommodate large plants and dramatic plant groupings.
Thus they have more substantial structural loads and need more frequent maintenance and watering.
To bear this weight an expensive custom support structure is required.
Besides the visual impact of an extensive green roof they also provide a natural habitat for birds and insects.
Intensive green roofs have more soil and a deeper growing medium sometimes several feet that can support a more diverse plant selection including small trees.
Green roofs have traditionally been categorised as extensive or intensive.
You can compare an intensive roof to a normal garden and this is why an intensive green roof is also known as a roof garden or garden roof.
Intensive green roof garden roof roof garden an intensive green roof system is characterized by its variety of vegetation ranging from herbaceous plants to small trees with professionel maintenance and advanced green roof irrigation systems.
They generally have lower water requirements and use small low growing plant species particularly succulents.
The growing medium depth for an extensive green roof system is typically 6 inches or less.
A typical growing medium depth of an intensive green roof is 6 inches or more.
Another term for these green roofs is rooftop garden.
Considered by many to be the green oasis in a modern cityscape intensive green roof systems come with a whole new technology based on environmental consciousness directly improving the air pollution heat and many other issues.
A properly designed and installed extensive green roof system can cost 108 248 m 2 10 23 sq ft while an intensive green roof costs 355 2 368 m 2 33 220 sq ft however since most of the materials used to build the green roof can be salvaged it is estimated that the cost of replacing a green roof is generally one third of the initial installation costs.
They are usually accessible.
Intensive green roofs offer a great potential for design and biodiversity.
These are covered with low growing plants such as evergreen sedums.