June 15, 2009
The City of Toronto passed a bylaw on May 27 that makes green roofs mandatory on all classes of new buildings.

The by-law requires up to 50 per cent green roof coverage on multi-unit residential dwellings over six storeys, schools, non-profit housing and commercial buildings. Larger residential projects require greater green roof coverage, ranging anywhere from 20 to 50 per cent of the roof area.

Deputy Mayor Joe Pantalone, a major proponent of the new by-law, said, “This bylaw is a major part of the solution to climate change, the creation of green jobs and it represents a whole new mindset on how our cities approach the 20 per cent or so of surface area that are roofs.”

Industrial buildings were given a reprieve until January 31, 2011, while city officials explore options such as reflective white roofs that will help achieve the city’s environmental goals, without incurring heavy costs.

Toronto already requires green roofs on city-owned properties. The city has established a financial incentive of up to $5.00 per square foot for existing buildings, and is currently building a publicly accessible green roof on its city hall. The project will be unveiled at CitiesAlive (see accompanying story) in October. See www.citiesalive.org for details.

 Developers argue that green roofs bring capital and maintenance costs with little payback, but Steven Peck, president of Green Roofs for Healthy Cities, says opponents of this proposed bylaw are exaggerating the costs and minimizing the benefits. Deputy mayor Joe Pantalone noted that if green roofs spread across the city, the average temperature in August could be reduced by two degrees, meaning less energy would be needed to cool the city.

New York City recently passed a city bylaw that rewards building-owners who cover 50 per cent of available rooftop space with a green roof with a one-year property tax credit of up to $100,000. The credit would be equal to $4.50 per square-foot of roof area that is planted with vegetation, or approximately 25 per cent of the typical costs associated with the materials, labour, installation and design of the green roof.

Toronto hosting conference

The City of Toronto and Green Roofs for Healthy Cities will host the inaugural CitiesAlive World Green Roof Infrastructure Congress, this October.

CitiesAlive 2009 will gather the international green infrastructure community together to address the issues as they relate to environmental, social and economic needs. Green infrastructure embraces the relationship between green roofs and green walls, as well as other forms of urban greenery, such as urban forests.

The Congress will take place at the Sheraton Centre in downtown Toronto from Oct. 19 to 22. More than 1,000 participants within the building design, development, construction and management sectors, as well as policy-makers, government officials, students and the public are expected to take part in the event.