"The Toronto council this month got a look at a proposed green roof by-law that would make such installations mandatory on certain new developments with a gross floor area exceeding 54,000 square feet. The measure, which is a component of Mayor David Miller's environmental strategy, proposes greening 30 to 60 percent of the roof area, depending on building size. Exemptions include schools, industrial structures, low- to mid-rise apartment buildings and affordable housing."
"If adopted, the city of Toronto would be the first municipality in North America with a mandatory green roof by-law. Similar requirements exist in Japan, Switzerland, Germany and France, according to Steven Peck, president and founder of Green Roofs for Healthy Cities, an industry association based in Toronto. Mr. Peck said he expects the measure to pass. 'We have a very broad base of support for this,' he said."
"That may be an overstatement. The council was to vote on the by-law this week, but the decision has been postponed for a month so the city can consult with developers, who have loudly opposed the measure, arguing that it would scare away investment due to the high cost of green roofs."