Credit: Wikipedia

In Vancouver, there's talk about two big roofing projects – one natural, one unnatural, both costly and experimental in their way.

On the unnatural front, Premier Gordon Campbell and David Podmore, the construction exec in charge of revamping BC Place for the Olympics, are looking at the feasibility of putting a retractable roof on the domed stadium.

It's getting pretty close to 2010 for such an ambitious project, though. "Get it done right, on time and Podmore gets the gold," says the Vancouver Sun. "Blow it, either through delays or the myriad of engineering complications that come with a $150-million to $200-million re-engineering job, and he's got an Olympic disaster on his hands."

On the natural front, Vancouver's new convention centre is undertaking what Pete McMartin calls the "grandest and most ethically ambitious architecture in the city": a green, living roof of approximately 750,000 bundles of Hooker's onion, beach strawberry, broad-leafed stonecrop, pearly everlast, quatro sheep's fescue, and chamiso sedge – hearty coastal grassland plants of British Columbia.

The project isn't intended merely to be pretty; in fact, once completed, the horizontal slab will be invisible to everyone but the denizens of office towers near the convention centre. Instead, the builders are focusing on the functional benefits of the roof. They are:
—Reducing the "heat island" effect of conventional roofs in urban settings;
—Keeping the building cooler in the summer and warmer in the winter;
—Extending the life of the roof by shielding it from UV light;
—Producing oxygen, absorbing pollutants; and
—Providing a home to birds and insects

Workers started planting the roof two weeks ago; no word on when they will finish. You can view a slideshow of the new convention centre roof here.