The Green Roof Verdict

It’s been three years since the green roof was planted on Vancouver’s new convention centre.

The Vancouver Sun recently wrote an article on the verdict of the roof. “Is it a success? Is it as good as they promised it would be?” the article evaluates by saying:

Some parts are terrific – attractive, quality planting; a beautiful habitat for songbirds and insect life. Other areas are untidy, scrubby, a bit of a mess; you might even say, an eyesore, and a fair ways from what they could or should be. Overall, the roof is more a success than a flop, but there’s definitely room for improvement, so the designers should not spend too much time pat-ting themselves on the back. There’s still some refining work to do.

Covering 2.4 hectares (just over six acres), it is still the largest living roof in Canada and the largest non-industrial green roof in North America. But being 10 storeys above ground, you can’t see much of it from street level, say from outside the Fairmont Pacific Rim at  Canada Place.

The lack of public access was always one of my main criticisms of the roof design – its failure to incorporate sufficient access for the public to get up there and actually enjoy the views. It would have been favourable to have a garden-like viewing area where people could see the meadow on the roof as well as panoramic ocean views, the article reads.

To summarize more details about the roof:

More than 400,000 native B.C. plants representing 25 species were used to cover the six acres of roof space. In addition, 40,000 bulbs were planted and 128 kilograms of flower and grass seed sprinkled to create the equivalent of the “coastal grassland,” the kind of look you are most likely to see on the exposed northern tip of Vancouver Island. 80,000 sedums were densely planted to form a massive carpet of colour and texture on the sunny west side of the building. (Unfortunately, this is not visible to the public, except on a special tour).

The roof’s wild-meadow look has been achieved by planting mainly three types of common grass – Idaho fescue (Festuca idahoensis), red fescue (Fes-tuca rubra) and Quatro sheep fescue (Festuca vugaris). Dozens of wildflowers, including Douglas asters (Aster subspicatus), nodding onion (Allium cernum) and common camas (Camassia quamash), have enabled bees from four hives to produce 120 pounds of honey. The grass on the roof is mowed once a year. Maintenance crews also make weekly visits to check drainage lines and to pull out invasive weeds.

It finishes with a quote, “The project continues to get a lot of attention because it strikes at the heart of an issue that we all hear about and are interested in – global warming and the loss of habitat through urbanization”.