When designed and installed properly, a greenroof is a truly sustainable solution that benefits the environment in many ways, over the short and long term. The following are some of the major ecological benefits of a greenroof:
Improves water quality
Greenroofs are a wonderful solution for reducing drainage flow rates, therefore preventing harmful stormwater from entering streams, lakes and watersheds. Plus, the greenroof’s vegetation and soil media trap and bind pollutants, which prevents them from being carried away by runoff and into our water systems.
Reduces air pollutants
The soil and vegetation on a greenroof act as filters, trapping dust, smog and other harmful pollutants from the air and rainfall. Also, by lowering energy requirements for air conditioning, a greenroof helps to decrease the building’s emission of greenhouse gases.
A greenroof reduces the energy required to heat and cool the building; rainwater can be captured and reused for numerous purposes, including irrigation.
Creates a biodiverse habitat
Birds, butterflies, bees and other insects lose their natural habitat to development. But a greenroof restores that habitat and creates a small but important refuge for wildlife, such as allowing birds to nest where they otherwise couldn’t.
Reduces urban heat island effect
A greenroof mitigates the urban “heat island” effect by cooling and humidifying the air around it, creating a favorable microclimate. Of course, a greenroof here or there won’t have a measurably cooling effect on a city’s air temperature overall, but think of it this way—every greenroof means one more building that’s helping just a little instead of contributing to the problem.