Wood reaches new heights as a building material
Timber-frame revival may gain even more momentum with new federal funding
George Brown College has steadily grown since its establishment in 1967 and now operates out of more than a dozen buildings spread throughout Toronto's core. One of its future facilities will be the most unique.
The public college of 26,000 students plans to erect a 12-storey tower framed of wood at its waterfront campus on Lake Ontario to house its computer technology program and a centre for researching climate-friendly building practices. It will complement a nearby existing health sciences building and a new design school that's opening in 2019.
Once ready in 2024, the tower dubbed The Arbour will be the highest wood-framed building for institutional use in Ontario and a significant milestone in the revival of timber as a construction material for tall structures.
"The future is certainly wood," says Shane Williamson, a principal at the architecture firm Williamson Williamson Inc. in Toronto.
Wood was a dominant building material in Canada's early days for commercial and residential properties, but it gradually gave way last century to safer and sturdier materials like concrete and steel as building heights grew. But with new safety and engineering insights into timber, tall wood buildings are making a strong comeback.
The revival may gain even more momentum under a new federal government program announced this fall. The Green Construction Through Wood initiative, meant for buildings 10 storeys and above, will provide nearly $40-million in funding to developers over four years, starting in April of 2018. The deadline for applicants is Dec. 6.
Ottawa is also expected to push along revisions to the National Building Code of Canada that would allow tall wood buildings to go beyond the current limit of six storeys. (Provincial limits differ and vary.)
George Brown has already put in its bid for some of the program money. "The government of Canada's tall wood program is an excellent opportunity to create a low-carbon campus that's innovative, stimulating for student learning, and responsive to the needs of our future," says college president Anne Sado, who is hopeful The Arbour will help demonstrate the latest techniques in design and green construction.
George Brown plans to hold a competition to determine which company will design the building.
Mr. Williamson, who is also director of the University of Toronto's master of architecture program, says there is a "tremendous" amount of interest from other builders, too, as they reawaken to wood's green and efficiency virtues.
"It's a cost-effective approach to building tall," says Mr. Williamson, whose architecture firm recently captured a Canadian Wood Council award for a private multi-generational home it designed in Ancaster, Ont.
"There has been long-standing issues around combustibility with current building regulations to make everyone feel comfortable and safe. But we're building taller."
The Brock Commons student residence at the University of British Columbia may be Canada's best example of what he's talking about.
The 18-storey residence is the world's tallest timber structure and was erected in just 70 days after the wood components arrived on site. It's made of cross-laminated timber (CLT) and features some concrete and steel as well.
"Brock Commons and similar tall wood buildings around the world demonstrate the safe and practical application of engineered mass timber in larger structures," says John Metras, managing director of infrastructure development at UBC.
"The reduced carbon footprint of wood buildings can play an important role in the development of sustainable cities."
He says UBC will continue to use mass timber in building applications in the future, given the positive results of Brock Commons, which opened this year.
The wood movement is also spurred by product development. Montreal-based Nordic Structures has emerged as a leading manufacturer of CLT. Five rows of lumber are stacked and glued together, and can be used to make wall panels or floor and roof slabs, helping speed along construction.
Nordic recently completed Origine, a 13-storey residential project in Quebec City. It was able to build 13 storeys after a series of rigorous tests at the National Research Council in Ottawa showed wood's safety.
Mr. Metras compares the prefabricated mass timber components to a Lego set. The structures are efficiently assembled, reducing construction time, minimizing waste and cutting down noise impacts to surrounding homes and businesses.
"CLT in some ways can be considered a replacement for concrete," adds Mr. Williamson. "In many ways it provides similar characteristics while offering tremendous benefits."