Today I´m sharing an interesting article by Kaid Benfield, published at theatlanticcities.com:
In January of 2010, Toronto became the first city in North America to require the installation of green roofs on new commercial, institutional, and multifamily residential developments across the city. Next week, the requirement will expand to apply to new industrial development as well. Simply put, a green roof is a rooftop that is vegetated. Green roofs produce multiple environmental benefits by reducing the urban heat island effect and associated energy demand, absorbing rainwater before it becomes runoff, improving air quality, and bringing nature and natural diversity into urban environments. In many cases, green roofs can also be enjoyed by the public much as a park can be. Toronto’s requirements are embodied in a municipal bylaw that includes standards for when a green roof is required and what elements are required in the design. Generally speaking, smaller residential and commercial buildings (such as apartment buildings less than six stories tall) are exempt; from there, the larger the building, the larger the vegetated portion of the roof must be. For the largest buildings, 60 percent of available space on the roof must be vegetated. (...)
The triptych image above was developed by students at the University of Toronto to illustrate changes that could ensue from ten years of progress under the city’s requirements. Prior to the bylaw, Toronto was second among North American cities (after Chicago) in its total amount of green roof coverage.
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