Building with Wood and Mass Timber Making a Comeback

Image Courtesy of Heatherwick Studio

In the early days, when Canada was just being settled, wood was often the building material of choice. It was plentiful, easy to work with, and used for constructing houses and just about every other type of structure.

Over the years, though, concrete and steel elbowed their way into the picture. While wood was still used in construction, it gave up ground to the other materials deemed stronger and more fire-resistant.

Today, however, wood—or more correctly cross-laminated timber (CLT) and glued-laminated timber (glulam)—is making a comeback. New technologies have made the material much more appealing. It seems we are seeing a rebirth of wood, driven largely by climate change and the move to sustainability.

Later this year, Canada’s National Building Code will be updated to allow wood buildings up to 12 storeys, change from the present six. Some provinces have already moved to bring their codes in line with the national one.

Leading the Charge

British Columbia has been leading the way when it comes to timber builds. Presently, two elementary schools in Metro Vancouver—Bayview Elementary and Sir Mathew Begbie—are being built of mass timber. These two buildings are part of a pilot project to test whether the material can make the buildings safer and more resistant to earthquakes. Each school is two storeys tall.

According to Lynn Embury-Williams, executive director of Wood WORKS! BC, an industry-led program that promotes the use of wood for buildings, these projects may result in a shift in how schools are built.

“Designing with wood is favourable to concrete and steel because wood results in lighter structures which means that the weight on the foundations is less, and, of course, they can design shear walls and lateral systems out of CLT that are designed to take the resisting forces. Wood is light and flexible, so the buildings move well with the seismic forces. Wood is considered to be one of the best materials because of that,” Embury-Williams explained.

In the Works

A number of other mass timber projects are planned, underway, or have been recently completed in B.C.

The first-ever mass timber aircraft hanger has been announced for Kelowna International Airport and will be the first of its kind in Canada. The two-storey, 60,000-square-foot structure will use state-of-the-art floor and tall wall, wood-based systems to accommodate the large spacing between the structure’s columns.

Construction of a 12-storey mass timber hotel tower has also started in Kelowna. It’s going to replace the ground-level parking lot of an existing Ramada in the east end of the city. The 40-metre structure will be the first wood-frame high-rise and the tallest mass timber tower in the city. It will be constructed using partial encapsulation and exposed CLT glulam. 

The British Columbia Institute of Technology, meanwhile, is building a 12-storey mass timber student housing project with 464 dorms. The school is embracing mass timber because B.C. is a leader in its use, and this project is an innovative way to reduce the carbon footprint.

“Compared to more typical steel and concrete structural designs, mass timber is the most sustainable structural design solution as the wood structure captures embedded carbon,” says school spokesperson Amy Chen.

Another interesting build has recently wrapped up in Langford—a 10,000-square-foot warehouse made of CLT and glulam. The building holds the distinction of being one of Canada’s first mass timber warehouses using CLT and the third project in the city using the materials.

Tom Moore, founding partner of Studio 531 Architects, who was lead designer of the building, says it’s quite incredible.

“It’s almost entirely built out of timber. We were able to use five-ply mass timber panels that were constructed running vertically, and we have 24-foot ceilings inside the warehouse with free-standing CLT walls all around the perimeter of the building and the interior demising walls.”

Why the Revival?

There are many reasons that wood is making a comeback.

Wood is a great way to sequester carbon. Trees absorb climate change-causing carbon emissions. Harvesting forests to use lumber and then replanting the trees captures even a lot of greenhouse gas from the atmosphere. Presently, about 13 per cent of all Canadian emissions come from carbon embodied within building materials and during construction, according to the Canada Green Building Council.

Although the steel and concrete industries have made advances in recycling, it is tough for them to beat the renewable property of wood. This building material can be renewed via forest management programs. And, when wood is discarded, it breaks down quicker than plastic, metal or concrete.

There are also plenty of trees in Canada. The country has nearly 350 million hectares of forest—third only to Russia and Brazil—and the use of timber supports forestry workers and creates thousands of jobs.

Timber framing systems also provide inviting spaces, and studies have shown that people benefit from working and studying in such environments. Wood is also great at absorbing sound and minimizes echo in living or office spaces, only adding to the comfort of using such spaces.

The speed at which wood buildings can be assembled is an important part of wood builds, which translates directly into cost savings on labour. Wood is also viewed as seismically safer as it bends instead of cracking in an earthquake.