Why Green Roof?
Green Roofs Defined
Green roofs are defined as either 'extensive' or 'intensive.' Extensive green roofs are thin-layer, lightweight vegetated covers providing primarily ecological and economic benefits. Intensive green roofs are more heavily constructed to provide a rooftop with landscaping for social and recreational use.
Stormwater Management
Green roofs have been shown to retain 60-100% of incoming rainfall. Stormwater retention reduces sewer system overflow events and runoff of airborne contaminants. Green roof installations are recognized as effective tools for stormwater management in highly developed urban areas.
Energy Savings
Vegetated surfaces deflect solar radiation and reduce thermal loading of roof surfaces and building structures. Cooler buildings require less energy use by air conditioning systems. These features combine to reduce the Urban Heat Island Effect, a phenomenon of increased regional temperatures caused by thermally loaded cityscapes.
Roof Longevity
Vegetative covering extends the life of roof components 2- to 3-fold. Green roofs block UV radiation and reduce temperature fluctuation, adding decades to roof performance.
Additional Benefits
Green roofs provide a wide array of environmental, economic, and aesthetic benefits. These benefits include removal of airborne pollutants and greenhouse gases, acoustic buffering, production of oxygen, and community beautification.