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Kimberly Powell

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If green roofs were mandatory in cities would there be less development and building?

William McDonough knows the benefits that come from designing and implementing green roofs. McDonough has helped design living roofs for big companies such as Nike and Ford Motors. But many companies and homeowners overlook the benefits of green roofs. One benefit of green roofs is that they keep the internal temperature of a building steady throughout the year. The National Research Council of Canada found that having a green roof reduced the daily energy demand for air conditioning in the summer by 75%. Toronto is the first North American city to pass a law mandating green rooftops for all new residential, commercial and industrial developments. Any new construction with floor space of more than 2,000 square meters must devote between 20 and 60 percent of its roof to vegetation. But with green roofs comes an unwanted financial upfront cost. Will developers decide that the benefits outweigh the costs for installing green roofs?

If green roofs were mandatory in cities would there be less development and building?

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    May 26 2012: If green roofs were mandatory, it would likely open up more employment opportunities rather than omit them. If America followed suit and had similar reduces in daily energy demand, that would create a surplus of money to spend elsewhere, and lessen the weight of our current energy needs. All in all I think green roofs would be a worthy requirement.
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      May 27 2012: I agree with you Bre. If people are worrying about green roof requirements hurting the economy to the point where they would have to decrease spending on housing developments, they should consider the jobs that green roof construction would open. And in the long run, the money we save from energy expenditure, could be used for other important investments.
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        May 27 2012: More directly, the money saved from energy costs would translate to the building costs of the green roof. I wonder then, if there is really much of a "cost" in building a green roof if you consider a 5 or 10 year span of time.
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          May 27 2012: This was exactly what I was thinking. If we did have to cut back on development and building for this new requirement, it would only be for short term.
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        May 27 2012: Besides the economic costs, would the green rooftops create their own ecosystems? Would this help with the fragmentation of the surrounding ecosystems? I think this would allow for predatory birds to come back into the city and help keep the troublesome pigeons.
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          May 31 2012: I think it's very possible that green roofs could provide both permanent habitats, as well as migratory stepping stones for birds crossing urban landscapes. Birds obviously do well in urban parks and gardens, so I see now reason why this extension to the rooftops would not be beneficial as well.
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      May 27 2012: After reading all these comments and the great ideas about how green rooftops can create urban gardens and jobs I am now curious, are green rooftops popular in other countries? Does anybody know??

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