Green roofs provide a variety of benefits including lower energy costs, reduced stormwater runoff, amenity value, improved aesthetics, and prolonged life of waterproofing membranes. In urban centres green roofs help mitigate the 'heat island effect'. They can even provide habitat for wildlife and be used for food production.
There are many variables in the design and application of a green roof. Elements that need to be considered include:
- What is the overall objective of the green roof?
- How visible will the roof be, and will there be designs or patterns incorporated?
- What type of plants will be used and what depth of growing medium will be required?
- What is the budget for the installation and on-going maintenance of the green roof?
- Which green roof system will be used, and will the plants be established on the roof or will a pre-vegetated system be used?
- What is the structural load capacity of the roof?
- Will irrigation be required?
- Will the roof be accessible?