A green roof is a roof that is planted with low growing, drought resistant, indigenous vegetation in a shallow light weight growing medium. Green roofs do not require structural supports and can therefore be planted on existing roofs.

Some of the benefits related to the extensive greening of roofs both existing and new are;

• Roofs last longer as they are protected from the extremes and harsh effects of the local climate, in particular temperature. Roofs have been prolonged by two to three times.
• Both heating and cooling costs are dramatically reduced as extreme temperatures at the roof level reduce due to the vegetation growth.
• Water runoff after rain is much reduced in particular peak runoff, much of the water is retained on the roof to provide for the growth of the plants where it is returned to the atmosphere without overloading the already badly altered natural drainage systems, less pollutants reach our watercourses and oceans.
• Extensive roof greening can  provide habitat for a whole range of plants and other small wildlife from insects, to reptiles, to amphibians right up to birds and in some cases even to small mammals. 
• Improves air quality through the reduction of pollutants and heavy metals.
• Large scale roof planting will reduce the “urban heat island effect” through shading, heat absorption and evaporation cooling.
• Reduces noise pollution.
• Increases biodiversity.
• Fire resistant.
• Aesthetic benefits of a Green Roof are enormous, they reduce glare and foster a feeling of wellness.