Nine months into construction, crews in Prince George, B.C., have unveiled the facade of the first high-rise built entirely of wood.
Standing 30 metres high, the Wood Innovation Design Centre at 5th Avenue and George Street will be the tallest modern all-wood building in the world when it's completed.
"Once we leave the ground, there's nothing but wood," said the building's architect, Michael Green. "It's a really unique project from that point of view."
The province gave Mr. Green's firm special permission to build the university and office space as a pilot project outside the rules of British Columbia's building code, which has a six-storey limit for wood construction. The high-ceilinged building will have six storeys, but be as tall as most 10-storey high-rises.
Wood design is a building trend that has been steadily picking up steam globally, and regulators in Canada are increasingly looking to permit taller wood structures.
Earlier this month, the U.S. Obama administration urged Canada to take action to combat climate change and reduce its emissions.
Eric Karsh, an engineer who worked on the Prince George building, said he's seeing a renewed architectural interest in wood design where it wouldn't have been used 10 years ago – projects such as soccer stadiums (the Marie-Victorin soccer stadium in Montreal has heavy timber arches that span 220 feet); city halls (North Vancouver's civic building has a mass-timber atrium); and large art galleries (the wood supplier for the Art Gallery of Ontario's Galleria Italia in Toronto called it one of the most complex wood structures in North America).
Mr. Karsh said although the Prince George tower is the tallest wood structure to date, he doesn't expect it to hold its title for long.
Already, Melbourne, Australia, has a comparable wood tower that would clock in as taller than Mr. Green's if it weren't for an additional concrete storey. Norway, however, is planning a 17-storey all-wood high-rise that will soon eclipse Prince George's global record.
Mr. Green said the technology exists for 30-storey wood towers in Canada.
"We're going to see those pop up very soon in British Columbia," said Mr. Green, who has several 15- to 20-storey wood projects in the works that have been approved in B.C. but not yet announced.
Buildings account for more than 50 per cent of carbon emissions on the continent and 55 per cent of Vancouver's. But where concrete and steel make up about 9 per cent of the world's greenhouse-gas emissions, wood is a renewable material that stores carbon rather than emitting it, meaning it has a negative carbon footprint.
The net benefit of a kilogram of wood is that about a kilogram of carbon has been locked up and removed from the atmosphere. A 20-storey wood building takes the equivalent of about 900 cars off the road in carbon dioxide savings in a year.
New laws for wood use, such as the Wood First Act in B.C. and increasing heights for wood structures in Canadian building codes, have been met with backlash from the cement industry, which questioned the safety of wood towers, especially in a fire.
Gerard Sass, an engineer with Fire Protection Engineering, said, however, that wood structures can be built to perform as well as concrete by covering the wood in non-combustible materials such as gypsum.
"That material has to be damaged completely to allow for wood to participate in the combustion process in the building, which is very unlikely," he said.
In the case of the all-wood Prince George high-rise, Mr. Karsh said it was designed with a sacrificial charring layer that could be burned away in a fire, and leave the structure still intact.
The Prince George building is on track to be completed by mid-August.