T.O. takes going green plan through the roof

Putting a garden on your roof is a great way to make better use of city space, protect the environment and save money in the long term.

While Canada lags behind world-leading cities like Chicago for developing green roofs, Toronto recently vaulted into first place with laws requiring a portion of green roofs on a range of new buildings from Jan. 31 next year.

Green roofs use “growing media,” a blend of light-weight aggregates and organic matters, to support layers of life in the sky. There is a high-quality water-proofing system, a root-repellant layer that protects the water-proofing and a drainage layer to avoid pooling water.

“Green roofs provide more benefits than any other green building technology by far. There’s nothing that can even come close to touching it in terms of the diversity of benefits that green-roof technology can bring,” says Steven Peck, president of the Toronto-based industry association Green Roofs for Healthy Cities. “There are extensive green roofs, which are six inches or less, and intensive green roofs, which are more than six inches and are often called ‘roof gardens.’”

Peck says they improve air quality, can produce food, create green jobs and even be used as recreational areas. “Hospitals will often use their rooftops and roof parks for patients and staff. We’re seeing condominium owners creating roof parks for their tenants.”

They also boost energy efficiency and reduce noise. Peck cites a Ryerson University study that found Toronto could support 500 million square feet of green roofs. “There’s a lot of potential,” he says.

The Mountain Equipment Co-op store on Toronto’s King Street West installed its green roof in 1998.

“We just thought it was the right thing to do. We knew the benefits it offered and thought it was a worthwhile investment,” says Dave Robinson, sustainability co-coordinator for MEC. He notes the expense of green roofing was initially a factor, but says MEC has long since made the money back in efficiency savings.

“It acts as an insulation blanket in both the winter and the summer time, so you don’t have to use your heating and cooling systems as often,” he says. “A green roof will allow your roof membrane to last one-and-a-half times longer than your average rooftop.”

Once it’s installed, little work is required. At MEC, a company comes in four times a year to check on the “prairie” field on the roof, but otherwise it’s left to its own devices.