A sustainable roof over their heads

When the proposed green roof at the Hugh Garner Housing Co-operative finally comes to fruition, it will resemble a garden in the sky.

"It is costly, but our green roof will be large, 22,000 square feet, the largest green roof in Canada," says Eleanor McDonald, a member of the co-op's green committee who has lived in the Cabbagetown building since it opened in 1982.

Five years ago, the members decided to choose a green alternative to their roof, which would be installed when the time for renovations came. While the short-term monetary cost of a green roof exceeds that of a conventional roof (at more than $1 million), McDonald says the long-term payoff is worth it.

For years, the co-op had run a garden on the roof, but now they will be planting directly into the roof. A green roof is an extension of the roof and includes a waterproof membrane, a drainage system and soil and plants, and it can grow low-lying plants and some flowers.

"It is both visually appealing and environmentally friendly," McDonald says, adding that it cools the air on hot summer days and reduces energy use by cooling the building beneath it. It also lasts twice as long as a conventional roof.

Part of the roof will also be used as a social area, and one side will also have solar panels. The basic structure of the roof was completed in 2006, but residents are waiting for renovations to be completed on the rest of the building before construction of the green roof can continue.