As of April 30, 2012, new industrial buildings are required to comply with Toronto’s Green Roof By-Law, joining ranks with residential, commercial and institutional buildings that have been subject to Toronto’s green roof by-law requirements since January 31, 2010.
Green Roofs have a specific meaning under the Green Roof By-Law, indicated as: “An extension of an above grade roof, built on top of a human-made structure, that allows vegetation to grow in a growing medium and which is designed, constructed and maintained in accordance with the Toronto Green Roof Construction Standard.” While the Toronto Green Roof Construction Standards sets out the minimum requirements for the construction and maintenance of green roofs; the Green Roof By-Law also requires that the Ontario Building Code requirements be met. The application for a permit to construct a green roof must be made to the Chief Building Official on prescribed forms.
The Green Roof coverage requirements are increased in accordance with larger building gross floor areas. The application of a green roof coverage area is triggered by a size threshold of 2,000 square metres in the Green Roof By-Law. A height threshold is also apparent for residential buildings, as the requirements for green roof coverage area do not apply to residential buildings with a height less than or equal to the greater of six storeys or 20 metres. The chart below, reproduced directly from the Green Roof By-Law, provides the green roof coverage requirements for the different building sizes (double-click to enlarge image):
Benefits of Green Roofs
Green roofs are credited by the City of Toronto for:
• Reducing stormwater runoff that affects quality of local water resources which supply drinking water, are used for swimming, and serve as fish and wildlife habitat
• Reducing energy consumption
• Reducing the urban heat island effect and associated cooling costs
• Beautifying the City
• Creating of greater natural green space
• Providing opportunities for local food production
The above benefits have yet to be calculated on a City-wide basis.
Exemptions for Compliance
Exemptions to comply with the green roof by-law requirements are permitted subject to a cash trade off. Appropriately termed “cash in lieu of construction of green roof”, where variances are approved by the Chief Planner or exemptions are approved by City Council, the applicant shall pay for the reduced area of green coverage based on the average actual cost of construction of a green roof, which at the time of passing the by-law in 2009, was deemed to be $200.00/m2.
For more information on this topic, please go to the Toronto Green Roof webpage.
Yadira is an associate in Fogler Rubinoff’s Environmental law department. She joined the firm as a summer student in 2009, and articled with the firm in 2010-2011. Her practice is focused on advice and litigation relating to environmental approvals, including approvals regarding renewable energy, resource extraction and land use. She can be contacted at firstname.lastname@example.org