A green roof has a dual function; it is a roof system designed to promote the growth of various forms of vegetation on the top of buildings. It is also designed to support various forms of renewable energy and water collection technology to assist in supplying power and water to the occupants of the building. Although a green roof is only one element of a building, it is extremely important when considering the long-term sustainability of our buildings and their impact on the environment.
The environmental advantages of installing green roofs are widely known and include; thermal insulation, increasing the life span of the roof structure, minimising surface run-off, reducing the cities heat-island effect, producing renewable/no emissions energy which is fed into the electricity grid, collecting and supplying rainwater to minimise the burden on town water and reducing emis-sions through minimising the need for heating and cooling. There are many more advantages associated with installing a greenroof and these will be discussed later.
Every green roof has a series of components that aid in either protecting the building, assisting the growth of vegetation, collecting/harvesting rainwater or generating energy. These components include a root protection layer, substrate or soil layer and finally, a layer of vegetation. Green roofs also host technology such as PV cells, wind turbines and water tanks.
