Timber! Why an age-old building material is making a 21st-century comeback in Ontario

Under provincial rules, you can’t construct a wood-frame building more than six storeys tall — but new technologies and initiatives could change all that
By Diane Peters - Published on January 21, 2019
University of Toronto wood tower
U of T’s new 14-storey building on top of the Goldring Centre for High Performance Sport will be one of the tallest mass-timber-and-concrete hybrid buildings in North America. (MJMA and Patkau Architects/utoronto.ca)

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One of the University of Toronto’s latest building projects, a 14-storey academic building on top of the Goldring Centre for High Performance Sport, next to Varsity Stadium, is going back to basics — with a twist.

 

It’ll be constructed mainly of mass timber, and when it’s done, it’ll be one of the tallest mass-timber-and-concrete hybrid buildings in North America.

 

Yes, wood is back. The building material comes with a number of benefits — environmentally friendly, lightweight — and support from the Ontario government.

 

“You know what they say: everything old is new again. If you think about it, wherever trees grow, people have been building with wood,” says Marco VanderMass, associate and project design architect at Kirkor Architects and Planners in Toronto. “Over time, we lost faith in wood because of big fires.”

 

But today’s wood building products use what’s called mass timber, which is factory-made to be so dense and large-scale that it’s fire resistant. (We still have building fires because, even if you build with non-combustible concrete, steel, and glass, people fill buildings with flammable items.)

 

“This is a new kind of wood product; it comes out of R&D and scientific research,” says Anne Koven, adjunct professor of forestry at U of T and a member of the newly formed Mass Timber Institute, which promotes research and education on the material. “It’s about taking wood and putting it together in different ways. It’s been engineered to have certain properties, to be stronger and fire resistant.”

 

Today’s mass-timber building materials resemble a far sturdier form of plywood. The U of T building will be constructed with cross-laminated timber — engineered panels made with multiple layers of wood connected at right angles, making them extra-strong.

 

Such wood structures often end up concealed beneath drywall or panelling. But designers will sometimes leave the wood exposed so that it’s visible in interior spaces or on the exterior.

 

Architects, builders, and academics are increasingly looking to mass timber because wood is a renewable resource. “Mass timber is much more environmentally friendly than steel or concrete,” says Koven. The concrete industry is one of the world’s top producers of carbon, and steel is made from iron ore, a non-renewable, mined resource. Forests, on the other hand, reduce carbon. Modern forestry practices are making the industry more environmentally responsible.

 

And wood is light, which means it’s ideal for towers on top of existing buildings, such as the one at U of T. Koven says it could also be used on the upper parts of bridges.

 

Mass-timber products can be preassembled and then easily shipped to the building site. “This is what the buzz is all about,” says VanderMass. “Mass timber allows us to be more efficient with our resources with more assembly offsite, away from the job site.”

 

Because urban construction is so costly and causes traffic jams, New York City and London have been building more with preassembled mass timber — full walls, full floors, or entire rooms — in recent years.

 

Most mass-timber projects in Ontario use materials imported from Austria and Germany, which have made this a specialty. There are well-established manufacturers in Quebec and British Columbia (most mass-timber companies in Canada make, design, and preassemble as part of their services), but Ontario’s capacity is set to grow: Leaf Engineered Wood Products in Devlin (near Fort Frances), for example, recently started production.

 

The industry is a natural fit here: Ontario has ample forests, and 40 per cent of all construction in Canada happens in southern Ontario.

 

Provincial rules don’t allow for the construction of wood-frame buildings of more than six storeys — the new U of T academic building was granted a building-code exemption as part of the Ontario government’s $3.15 million Mass Timber Program, which it launched last spring to jump-start the industry.

 

The program’s other demonstration projects include a 12-storey building at George Brown College on Toronto’s waterfront, a condo development in downtown North Bay, and an eight-storey office building in Toronto.

 

Some of the money will also go toward education and research — for example, it’s helping fund the Mass Timber Institute, a partnership between U of T, George Brown, Lakehead University, Laurentian University, and the University of Ottawa.

 

Mass timber is on the rise, but it won’t become commonplace until building codes change (the Mass Timber Institute is already advocating for this), local supply chains make for cheaper prices, and large developers start using it.

 

To that end, designers and builders are trying to find the best ways to combine it with concrete, steel, glass, and other materials. “We need to come up with more ways to make hybrid systems,” says VanderMass. “That’s the future.”

Diane Peters is a writer and editor. She teaches at Ryerson University.

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