The University of Toronto’s motto “velut arbor aevo,” meaning “may it grow as a tree through the ages,” is coming to life with the construction of a tower made primarily of mass timber.
Construction is planned to begin this spring on a 14-storey, 80-metre-tall academic building that will be built on a frame made of wood instead of steel. To date, it’s the largest tall mass timber structure of its kind to go up in North America.
The Academic Wood Tower will be built with columns, decks, bracing and a core that are made of glue-laminated timber. Typically, Canadian spruce, pine and fir are used.
Mass timber building materials are made by using adhesive to mechanically fasten or bond smaller wood components, such as cut lumber or wood veneers, strands or fibres. The result is called cross-laminated timber (CLT) – large, prefabricated wooden beams, pillars, arches, walls, floors and roofs that can replace steel because it’s comparably strong and durable, as well as more environmentally friendly.
The Canadian Wood Council, which represents the Canadian lumber industry, says mass timber is dense, strong and efficient to build with. Termites are no threat because there’s no contact between the wood and the soil under the foundations of such buildings, chief executive Kevin McKinley says.
In terms of fire protection, wood can offer benefits, the council says. Unlike other fabricated materials, protecting wood from burning has been well understood since, well, the discovery of fire, and CLT is resilient.
“It’s kind of like plywood on steroids,” says architect Ted Watson, partner at architectural firm MJMA of Toronto, which is working with John Patkau and Greg Boothroyd of Vancouver’s Patkau Architects on the project.
He compares the threat of fire to a CLT beam with lighting a thick log with a single match – not so easy. According to MJMA’s preparatory research, “a partially exposed mass timber structure introduces no more risk than conventional tower construction.”
The Academic Tower is also being built for sustainability and climate change. Its wood framing replaces the steel beams that would normally be used for a building of this size, minimizing the carbon footprint of the construction and building materials.
“Steel and concrete contribute 5 and 8 per cent of carbon emissions into the atmosphere globally, through the process of manufacturing them,” Mr. Watson says. “Wood is actually doing the opposite. It encapsulates carbon.”
Mr. McKinley cites a tall wood housing building at the University of British Columbia that was constructed in 2017. By not using steel beams, he explains, the project saved the equivalent of the carbon that more than 500 cars would spew into the air in a year of driving.
Although the new building will still be made of concrete in addition to the wood, the carbon implications of this project are overall positive, says Scott Mabury, U of T’s vice-president of operations and real estate partnerships.
“We take our carbon reduction commitments seriously,” he says. “A building like this shows how we not only have a plan with objectives to reduce carbon, we have a plan for how to reach them.”
The university’s low-carbon action plan, unveiled last September, called for the school to cut its carbon emissions by 37 per cent from 1990 levels by 2030, curbing its annual CO2 emissions by 44,567 tonnes.
The project is being built in a tight space just south of the Munk School of Global Affairs and Public Policy, which faces Bloor Street West at Devonshire Place. It’s being constructed above the Goldring Centre for High Performance Sport, which Mr. Watson’s firm also helped put up in 2015.
The base for this future tower was actually built into the Goldring Centre, to minimize disruption and cost, Mr. Watson explains.
“After we completed the Goldring Centre, we had designed a steel structure for the tower. The university asked us to look at the viability of wood,” he says.
“Our research showed that while there’s an uptick in the cost when you use wood, on balance it delivers value,” he adds. The architects and the university decline to say how much the entire project will cost at this time.
In addition to the environmental benefits, the building is also being designed to be a showpiece. It will be occupied, in part, by the Munk School of Global Affairs and Public Policy and the Rotman School of Management’s executive programs, a mathematical finance program and the kinesiology and physical education faculty.
Airy and clad with vast expanses of glass, the tower is designed so it branches out wider at the top – like a tree, if you will. The wider top will hold an event space that offers dramatic views of the university and the city.
“We want people to notice,” Mr. Mabury says.
The university’s tower is also important because it supports the efforts of Canada’s forestry sector to find new markets for its products and stay at the forefront of technology innovation, Mr. McKinley says.
“There are also the intangible benefits. There’s a term called biophilia [the innate tendency humans possess to connect with nature and other forms of life]. It’s nice to live or work in a building made of wood,” Mr. McKinley says.
On the more tangible side, the wood council, the university and the forestry industry hope that the new tower will lead to more mass timber construction, new uses for Canadian timber and new, tech-based wood construction and research jobs.
The university has partnered with the Ontario government, Toronto’s George Brown College (which is also constructing a CLT building at the waterfront) and other private-sector organizations to set up the Mass Timber Institute to study new building techniques using wood.
There’s a bit of a worldwide race to build biggest timber tower now, Mr. Watson says.
“The Norwegians just built one which is now the tallest. It’s hard to know which new project will eventually be the biggest. But we do know that ours will be exceptional.”