It is an age-old material with a stigma around fire safety that means it is often overlooked. But today, in Canada, wood construction is making a significant comeback as architects, engineers and designers search for renewable materials capable of creating functional and sustainable spaces.
In recent years, a string of new “mass timber” buildings have cropped up across the country – from an 18-storey student accommodation block in Vancouver, to a 14-storey academic tower in downtown Toronto. Plans for the “world’s tallest hybrid wood tower”, also in Vancouver, were recently unveiled by the firm Perkins+Will.
The new structures have helped propel Canada to the forefront of the timber construction industry, which was originally developed in Europe but is now gaining traction elsewhere as demand grows for more sustainable building options.
“We find many clients fully willing to embrace timber in their buildings,” says Derek Newby, an associate architect at Perkins+Will.
Unlike traditional timber-framed buildings, mass-timber structures – often dubbed “plywood on steroids” – use thick solid timber panels that can support buildings far higher than ordinary wood. Categories of mass timber include cross-laminated timber, glue-laminated timber and nail-laminated lumber.
Constructed this way, proponents say timber does not ignite easily and forms an outer char layer that protects the inner structure from fire. The material is considered a sustainable alternative to steel and concrete, which both create large amounts of carbon dioxide during construction.
“Timber is the only structural material we have that is made by the sun,” says Newby. “That is a profound but simple thing: if you don’t grow something you have to mine it, and that tends to be very energy-intensive.”
The fact that wood is environmentally friendly makes it a popular option with consumers, Newby adds, even if the construction industry and some governments are showing little interest in combating climate change.
“As a natural resource it is something that everyone understands,” Newby says. “People have an association with wood, everyone understands its use and how it behaves, it just resonates.”
Canada stands tall
In many ways it is unsurprising that mass timber is catching on in Canada. Wood has always been an important part of the country’s construction industry with British Columbia in particular home to vast forests of softwood lumber, and a wood industry that supplies the world.
“We did a lot of buildings [using wood] in the past for warehouses and we are now reinventing those kind of buildings with engineered mass timber,” says Marco VanderMass, a Toronto-based associate and project design architect at Kirkor Architects. “We have always worked with wood for suburban housing too. It’s one of the most readily available materials and our builders are very familiar with it.”
Support mechanisms are also helping push things forward. In British Columbia, the 2009 Wood first Act encouraged design teams to explore the possibilities of building with wood, while a recent federal program called The Green Construction Through Wood initiative is providing a further $40m in incentives to developers using the material.
“The federal government recognises the role wood can play in our climate commitments and our desire to reduce greenhouse gas emissions,” Newby says. “It has been incentivising research and demonstration projects that use timber throughout the country.”
Going forward, VanderMass, who has been researching and working with wood applications since the mid-1990s, says he would like to see more mass timber projects manufactured off-site to shorten project timelines and improve safety and quality.
“Anything that we can produce that is more lightweight can potentially be built in a factory under much more protective conditions which means we get a better quality product,” he says.
To move forward with mass timber, however, Canada will need to continue revising its building codes. While places like Ontario and British Columbia have relatively progressive attitudes towards mass timber, other parts of Canada are still lagging behind.
More capacity to fabricate and construct mass timber buildings will also be needed. While there is no shortage of architects, engineers and builders who understand concrete construction, “with mass timber, capacity is still lacking,” says Newby.
“We have a reasonable-sized industry in Western Canada, in particular putting up timber buildings, but we could use more capacity for the construction for it to become a commonplace thing,” Newby adds.
Above all, the industry will need to win further acceptance from the public, construction industry and authorities. In the past, fires related to wooden houses caused huge amounts of death and destruction, while further doubts remain about the material’s long-term durability, acoustic quality and ability to withstand earthquakes.
“We know that we can make timber buildings every bit as safe as those other construction methods, but there is a perception to overcome with the public around all these things,” says Newby.
But none of these issues are considered insurmountable and Canadian architects say they will continue to push forward with new, experimental projects that demonstrate the value of mass timber.
In May, Newby’s firm, Perkins+Will, unveiled plans for an “Earth Tower” in Vancouver, British Columbia, that will become the world’s tallest hybrid wood tower – at 40 stories – if planning permission is granted.
Built to Passive House standards, the material used will “dramatically” reduce the project’s greenhouse gas emissions through carbon sequestration, according to the firm, while other features will help restore local biodiversity and provide accessible spaces for the general public.
“The idea is to show that a market-oriented project can have sustainability goals and actually do something about emissions and the environmental consequences of building,” says Newby. “In that respect, the project is visionary.”