The North American green roof industry saw a 115 percent growth in 2011, up from 28.5 percent growth in 2010, according to the Green Roofs for Healthy Cities (GRHC) 2012 Annual Industry Survey of Corporate Members.

With more than 500 accredited Green Roof Professionals (GRPs) in the market committed to driving industry growth, the future looks bright for these sustainable structures. Since green rooftops are becoming much more than just a hot new trend, it may be time to examine their benefits.

Advantages of green rooftops include:

Heat reduction
A green roof’s plantings and barriers keep the top floor of a building significantly cooler than a traditional roofing system by protecting against the sun’s constant, direct radiant heat. By absorbing heat, green rooftops also lower ambient temperature, thus aiding in the reduction of “urban heat island” impact to be more consistent with the surrounding countryside.

Stormwater management
Green roofs can intercept between 15–90 percent of rooftop runoff, helping to reduce the amount of storm water entering local waterways. During periods of heavy rainfall or snowmelt, green roofs can help divert water from the sewer systems, preventing overflow into nearby bodies of water.

Increased energy efficiency and lower utility costs
By deflecting heat and with a layer of vegetation and trapped air, green roofs offer increased insulation, in turn resulting in reduced energy use and electric expenditures.

Extension of the life of a conventional roof
When installed correctly, a green roof can extend the life of a conventional roof by three to four times by protecting the roof surface from UV light, preventing large temperature fluctuations and combating normal wear and tear associated with exposed-surface roofs.

Public image
Installing a green roof can help your clients make a highly visible statement, showing their clients and other community members that they are taking part in mitigating climate change, combating air and water pollution and increasing biodiversity. It also provides an opportunity for them to showcase their sustainability policy and garner positive press.

All the extras
Green roofs are good sound insulators, reducing the impact of noise to areas below the roof. What’s more, air quality improvements from a green roof’s plant photosynthesis reduce the negative impact of carbon dioxide and produces oxygen, helping to filter out airborne pollutants. Finally, with a little creativity, green roofs can also incorporate gardens, accommodate threatened native plant species and even offer food supply for birds and insects, further helping to improve sustainability and biodiversity.