Cities across Canada are facing high demand to build, and to build fast. From housing to key infrastructure, the question is being asked about how we build faster while still delivering on sustainable and environmentally friendly design. The answer? Build with wood.
This historic building method is back, and in large part because Canada’s forests are a valuable asset in the fight against climate change, serving as critical carbon sinks. But as trees age, they begin to lose their ability to absorb carbon and become more susceptible to pests, disease and fire – natural disturbances that can release tremendous amounts of CO2 and other GHGs back into the atmosphere.
That’s why it’s critical to harness the full carbon capture potential of forests through sustainable forest management – something that Canada’s forest sector is a world-leader in. It includes carefully planning the future of forests, one element of which is selective harvesting. This allows the trees left behind to grow bigger and more resilient to pests, disease and fire, then replanting trees that absorb the most carbon while they are young and growing.
Trees that leave the forest continue to store carbon, and that’s where building with wood comes into play. In construction for example, wood products such as lumber and mass timber (made by layering laminated and compressed wood) keep carbon locked in for many years, moving the carbon capture potential of forests into cities.
And because Canada’s forest sector manages the country’s public forests sustainably and responsibly, this carbon capture potential can be maximized by building homes, bridges, shopping malls, schools – and others – with wood.
“Most of our new buildings are filled with petrochemicals,” says Kelly Alvarez Doran, co-founder of Ha/f Climate Design and a professor at the University of Toronto’s faculty of architecture, landscape and design. “In contrast, a century ago our buildings were made of stone, earth, wood, straw and hemp. It is exciting that we are now looking to these materials again.”
“These low-carbon materials have been removed from our buildings and from our construction supply chain systematically – and we need to systematically bring them back. How does a country covered in forests and fields have any excuse but to not have bio-based construction? Nearly every part of a building could be grown. We need to wean our buildings off petroleum quickly.”
Mass timber products like CLT, or cross-laminated timber, can replace large-span, concrete floor slabs. Glulam (glue-laminated timber) can replace concrete or steel beams. Wood fibre board and cellulose insulation can replace fossil-fuel derived insulations.
“One option is accelerating climate change, and then there’s wood and other bio-based materials, which could serve to mitigate it,” Doran explains.
Conventional construction in Canada is highly carbon intensive, using mainly concrete, aluminum and steel. Wood, on the other hand, is a natural and renewable construction material. This means that mass-timber buildings can reduce the carbon footprint of construction by up to 45 per cent and can also be completed 25 per cent faster. They also require less energy to heat and cool long-term.
Craig Applegath is partner at design firm DIALOG and chair of the Mass Timber Institute at the University of Toronto. Considering climate change is accelerating, he points to the accessibility of mass timber as an already available and proven solution. “We need to lock up as much carbon as we can as fast as we can. Sustainably harvested mass timber stands out as a solution we can implement right now and we should be using it in as many buildings as possible.”
There are incredible mass timber buildings and structures in Canada, from bridges and libraries to company headquarters and Montreal’s new Formula 1 paddock. But progress is needed to see them become the norm, not just the attractions or exceptions.
Most mass-timber projects are made to order, so there is much less waste. Buildings can even be designed for disassembly when they need to be rebuilt, and most of the products can be recycled or reused, so they remain a “carbon bank.” This points to the circularity of mass timber, an attractive feature in collective efforts to reduce waste and ensure the reusability of products long-term.
“It’s really important to understand the power of trees to store carbon and then work with nature to incorporate that benefit into our built environment. Sustainably harvesting trees like our forest sector here in Canada does, that’s key for mass timber to make true environmental sense,” adds Applegath.
Canada’s forest sector is committed to the sustainable management and stewardship of the country’s public forests, enabling them to capture and store as much carbon as possible – because that’s the most important thing. It’s about the forest. Mass timber is a means to that.
To learn more about Canada’s forest sector, visit forestryforthefuture.ca
Advertising feature produced by Globe Content Studio with Forestry For The Future. The Globe’s editorial department was not involved.