Craig B. Rushton

Via The Vancouver Sun

VANCOUVER — Vancouver’s roofs are getting greener — with the city in a front group of North American cities embracing the living-roof movement, says the city’s deputy manager.

Sadhu Johnston wasn’t surprised to hear that Vancouver ranked fourth on the continent for square footage of green roofs added in 2008 — the most recent available data.

“Vancouver has been a leader on this for a long time and on a per-square-foot basis we are near the top of the list,” Johnston said on Thursday, which was Earth Day.

Chicago has more green roof coverage than any other city, followed by New York, Washington, D.C. and then Vancouver, according to Green Roofs for Healthy Cities, a Toronto-based group that advocates for the industry and tracks its growth.

Vancouver’s high ranking for 2008 is mostly due to the 2.4-hectare “living roof” on the Vancouver Convention Centre, said Steven Peck, president of Green Roofs for Healthy Cities. The centre’s green roof is the largest in Canada.

But Johnston said it’s not a “one-off” for Vancouver. The main branch of the Vancouver Public Library has a green roof, as do 50 per cent of roofs on the Millennium Water project in southeast False Creek, he added.

“The convention centre roof is definitely the most visible one but green roofs are all over the city,” said Johnston. “There are new green roofs being built virtually every day.”

Johnston, who left his former job as environmental czar in Chicago to head Vancouver Mayor Gregor Robertson’s greenest-city initiative, said green roofs provide a range of economic, ecological and esthetic benefits.

“They absorb water so you get less storm water going into your sewers. They cool down the city on a hot summer day. They provide habitat and food for wildlife. They offer beauty for humans to enjoy and can be used as outdoor play and recreational areas.”

Johnston said the city encourages green roofs and often demands their inclusion in development proposals requiring rezoning.

But so far, Vancouver has not adopted Chicago’s policy of offering incentives to builders who put green roofs on their buildings. Chicago has about seven million square feet of green roofs. Its city hall’s green roof is one of the best-known examples of the roofs in the U.S.

Vancouver has also not followed the example of Toronto, which recently passed the first bylaw in North America establishing standards of mandatory green roofs. Starting this year, any residential building over six storeys in Toronto must have up to 50-per-cent green roof coverage.

While the green-roof phenomenon is in its infancy in North America, it’s been common in Germany for many decades, said Peck, from Green Roofs for Healthy Cities.

Between 15 to 20 per cent of flat roofs in Germany are green, he added.

Peck said that square footage of green roofs in North America has been growing at about 30 per cent each year since 2004.

Despite the high rate of growth, green roofs are still a small segment of the roofing industry, said Peck.

“Green roofs account for less than one-tenth of one per cent of the entire roofing industry in North America.”

Cost remains a disincentive for builders, added Peck, saying a properly installed and designed green roof system can cost up to $15 per square

dward@vancouversun.com