Branching Out: Architects and builders return to wood
Wood has long been the standard in residential construction, but recently it's being seen as viable material for all kinds of projects
by Alix Kemp
Photo Steve Nagy Photography
When architect Lloyd McLean and design firm Russell and Russell first conceived of the Grizzly Paw Brewery in Canmore, they imagined a modern steel structure. “The reason for that wasn’t necessarily that we didn’t want to use wood,” says Alasdair Russell, who owns Russell and Russell Design Studios with his wife. “It was just conceived as an industrial building. We just assumed it was going to be a fairly cost-effective steel building.”
But during a two-year delay in construction while the lot was being subdivided, the price of steel quadrupled. The price of timber, on the other hand, hardly budged. Not only that, but it turned out that wood was better suited to the complicated serrated roof design that would have been a challenge to fabricate from steel, and was also aesthetically a better fit for a brewery nestled at the foot of the Rocky Mountains. Despite its delayed beginnings, the Grizzly Paw Brewery went on to win the 2013 Prairie Wood Design award for commercial and industrial projects.
Wood has long been the standard in residential construction, where wood-framed single family homes are the norm. But in recent years, builders, architects and designers have started seeing it as a viable construction material for all kinds of structures, including multi-storey projects and industrial buildings. “It’s a fantastic material that looks good and can be used virtually anywhere,” says Russell. That’s something Brady Whittaker, president of the Alberta Forest Products Association and the executive director of Alberta WoodWorks! is excited about. “Building with wood is just the right thing to do,” he says. He says wood buildings, on average, are 10 to 20 per cent cheaper to build, and are also less expensive to maintain and operate. Wood is also a renewable resource, and wood products are responsible for much lower greenhouse gas emissions than concrete or steel.
Technological advancements and the creation of new wood-based construction materials mean that the range of buildings that can be made from wood has expanded significantly. One of those developments is cross-laminated timber (CLT), large panels of wood that are created by fusing multiple layers of wood with adhesive. CLT is strong, durable, fire-resistant and can be pre-finished, a property that’s especially valuable given Alberta’s short construction season. Like most wood, it’s also environmentally friendly and energy efficient. That’s why it’s being used to build the roof of the new Fort McMurray airport, the largest structure in North America to employ CLT.
It’s because of technological advancements like CLT that wood is now being used in structures as high as 10 storeys in Europe and Australia. Closer to home, the six-storey Wood Innovation and Design Centre in Prince George, B.C., is slated to become North America’s tallest wooden building when it’s completed later this year. Although the National Building Code of Canada currently restricts wooden buildings to four storeys, B.C. and Quebec allow wooden structures up to six storeys. So far, however, Alberta hasn’t embraced wood construction to the same extent, and hasn’t passed its own building codes to allow the construction of larger wood buildings. “Unfortunately, Alberta generally prefers to wait for the rest of the country in this area,” says Whittaker. But the rest of the country is catching up – changes to the National Building and Fire Codes are expected in 2015, and a proposal to increase the maximum height for wooden construction from four to six storeys is under consideration.
Of course, not everybody is excited. The Cement Association of Canada has been fighting the proposed change to the NBCC, arguing that taller wooden structures will increase the risk of fire, and the Canadian Concrete Masonry Producers Association purchased advertisements in the Toronto Star to argue that wood construction was responsible for deforestation and was more susceptible to fire, insect infestation and other problems. Both organizations are responding to the “Wood First” initiative in B.C. that encourages builders to consider using wood instead of other construction materials to make use of the millions of trees affected by the mountain pine beetle.
Whittaker disagrees with their claims that wood is less safe than concrete or steel. He says wooden structures are only especially vulnerable to fire during the construction phase, when all buildings tend to be more susceptible to damage, and that it’s a problem the construction industry has addressed by installing sprinklers to suppress potential fires during construction rather than after the drywall goes up. A 2013 study by the University of the Fraser Valley found that sprinklers more than mitigated any increased risks from mid-rise wooden buildings. In fact, in certain scenarios – earthquakes, for instance – wood buildings can be sturdier than their steel and concrete brethren. And Whittaker says he doesn’t support the use of wood to the exclusion of concrete or steel. “I think the best buildings are actually made from a combination of materials,” he says.
Michael Green, the architect who designed the Wood Innovation and Design Centre in B.C., delivered a TED talk on the potential for wooden skyscrapers in 2013. Green hopes that we’ll eventually see wood buildings of up to 30 storeys. That will depend largely not on whether it’s possible to build such enormous structures out of wood, but whether consumers can get over their fears that such structures are bound to go up in smoke.