The Globe and Mail recently ran a story on green roofs in the City of Toronto. BILD’s Toronto Chapter Co-Chair Leona Savoie, who also works as Director of Land Development and Acquisitions for Hullmark Developments, was interviewed by the Globe’s Brenda Dalglish about the industry’s experience with the City’s green roof bylaw.
In 2009, a bylaw was implemented making green roofs mandatory on all new commercial, industrial and public buildings with roofs larger than 2,000 square metres. There are, of course, specifics and exceptions when it comes to requirements, Leona explained. For example, low-rise industrial buildings have lower requirements while high-rise condominium towers are exempt from the rule due to the increased amount of wind. Sedums are the most popular plants used in green roofs because of their ability to withstand extreme heat and sun, but they are powerless against the strong winds that intensify as the building gets taller.
There are now 135 green roofs in the city, with about that many under construction. There are a few different types of green roofs with the main variations being intensive and extensive. With an intensive green roof there is typically a larger variety of plant species and a deeper growing medium. These roofs require more maintenance and often serve as recreational areas. Extensive green roofs have a shallower growing medium require almost no maintenance and are designed to be functional rather than aesthetic. The City of Toronto website offers a fairly detailed explanation, at least for a layperson.
Another key issue is whether the roof is new of retrofit, with the latter being more expensive and complicated to implement.
When asked about the industry’s reaction to the green roofs bylaw, Leona explained that developers initially resisted, but came around to accept the program. “I understand there was quite a bit of resistance from the industry at first,” she said. “They wanted to let the market figure it out and then everyone would follow the best practices that emerged. But the city consulted with the industry before the bylaw was introduced and the members I’ve spoken with say it’s working well.”
She also explained that while the program has been in place for a few years, the majority of the buildings built in accordance to the bylaw have not yet been built. “It’s too early to say whether it’s been successful. We’re not going to know for five to ten years how they hold up and whether they’re doing what they are supposed to.”
In case you haven’t been on a helicopter tour of the city lately, green roof buildings include Metro Toronto YMCA, Ryerson and York Universities, City Hall Podium and the York Civic Centre to name only a few. BILD continues to work with its partners at City Hall to ensure the program meets the needs of residents and new homebuyers.