A green roof is an extension of an already existing roof consisting of vegetation, growing medium, filter and drainage system, and structural support in an interlocking grid. Green roofs counteract the urban heat island effect, which is when temperatures in a city are hotter and drier than that of the surrounding countryside. By reducing impervious surfaces which cause temperatures to rise, green roofs cool the air through the process of evaporation and assist in keeping the rooms beneath the roof cooler. Green roofs also absorb sound from both the interior and exterior, blocking noise such as highways or airplanes and help prevent excess storm water runoff. Another advantage is the reduction of smog and dust, because it is known and proven that plants can enhance the quality of air. With these benefits for green roofs being stated it is very hard to find a suitable argument for bare or graveled roofs.
Germany has many policies in place now including building code guidelines, minimum design requirements, and performance standards. They also give direct and indirect financial incentives and ecological compensation to property owners and developers through integration into developmental regulation. Canada is in the beginning stages of creating polices and already offers incentives to commercial and institutional buildings for green roofs that improve energy efficiency. Green roofs also count towards Leadership in Energy and Environmental Design (LEED) certification points for Green Building accreditation evaluation.
The United States is just discovering policy and planning importance in the green roof industry. Green roof knowledge is very limited according to a survey given to 2,500 facility managers in the United States. It found that most facility managers knew about green roofs principles and some advantages but not their full purpose. Raising awareness for green roofs and their benefits would be the first step towards policy and planning in the United States. Future policy to consider would be requiring buildings within cities with a certain number of square foot roofs to install green roofs and to give these developers grants and incentives.
-Amanda Hamilton
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Last semester we watched a video in Global Environmental Issues about how Cuba had an organic farming revolution during the U.S. trade embargo. Much of the video focused on how cities took advantage of green roof practices to develop within the area. I thought it was an amazing story of sustainable development. Contractors seem to still question green roof techniques here in America, though, so I think there should be extensively publicized research about their impacts on the buildings themselves. There is enough research out there to show how great they are environmentally.
ReplyDeleteKELLEY JUNCO
Sometimes it is hard for older buildings to structurally support the weight of a green roof, but I think that mandating a part of the roof be a green roof in new buildings is a great idea. I would really like to try to get a central one on campus, and have it be an educational experience for students and everyone. Could Blacksburg support the growth of some fruits of veggies all season, do you think? Or would we have to stick to other plants if we had a green roof on campus?
ReplyDeleteThough the idea of Green Roofs is relatively new in the US, like you said, there is a growing number of architects, engineers, urban ecologists and city planners that are especially in favor of the use of green roofs. Some high-profile green roofs that have been built within the past few years can be seen atop Chicago's City Hall and a Ford Motor Co. facility in Dearborn, Michigan. Green roofs are even starting to sprout up in New York city, a library in Indiana, and on top of a Multnomah County Building in Portland, Oregon.
ReplyDeleteI really wish we had more green roofs in our country currently, but I do believe that the green roof trend has begun to take its roots in the US.