The new Toronto Green Roof By-law requires a green roof for all new development (residential, commercial and institutional) that measures at least 21,500 square feet starting in 2010. For industrial property, the requirement begins in 2011. The city adopted the by-law last week. The law calls for a graduated coverage requirement ranging from 20-60 percent of the available roof space, excluding industrial. The coverage for industry buildings must equal 10 percent of the available roof space up to a maximum of 21,500 square feet. Toronto already requires green roofs on city-owned properties. Deputy Mayor Joe Pantalone told the Globe and Mail the new requirement was “an opportunity rather than a handicap.â€
http://www.toronto.ca/greenroofs/overview.htm