B.C. proposes changes allowing mass timber up to 18 storeys

Key Takeaways:

• The Province of B.C. is proposing code changes that expand what builders can do with mass timber, including constructing structures up to 18 storeys.
• The changes would also allow for more exposed mass timber or fewer layers of encapsulation in buildings, depending on a building’s height.
• Officials say the changes would allow buildings, such as schools, shopping centres and housing to be built faster.

The Whole Story:

Mass timber may soon be going to new heights in B.C.  

Officials announced proposed changes to the building code that would enable taller mass timber buildings, as many as 18 storeys for residential and office buildings, instead of the current 12-storey limit. 

The changes would also allow for more exposed mass timber or fewer layers of encapsulation in buildings, depending on a building’s height, and allow more building types, such as schools, shopping centres and industrial facilities, to be built using mass timber.

Officials say the changes would allow buildings, such as schools, shopping centres and housing to be built faster, leading to a better environment and economy.

“These proposed mass timber building code changes align with our recent work to deliver more homes near transit hubs by allowing taller buildings and more sustainable housing options near transit,” said Ravi Kahlon, minister of housing. “These changes will also help reduce carbon pollution, support the forestry sector, create jobs, build more homes and lead to more vibrant, healthier communities.”

The proposed changes are posted for public comment on the Canadian Board for Harmonized Construction Codes website. After the comment period, the B.C. government will decide on what changes are ready to move forward and what changes, if any, need further technical analysis. Key changes are expected to be adopted as soon as spring 2024.

B.C. and Quebec spearheaded a joint task group to develop the proposed code changes on an accelerated timeline to expand mass timber in Canada. Once the public comment period is complete, a package of proposed code changes will be made available to provinces and territories to consider for adoption in their codes, and for future consideration for the national building codes. These proposed changes have also been reviewed by an expert technical advisory group made up of fire safety experts, regulators, engineering and building code experts from across Canada.

B.C. has a history of going tall with mass timber .Builders in B.C. made history in 2017 when they completed Brock Commons, a 12-storey student housing tower at the University of British Columbia. At that time, it was the tallest mass timber building in the world and required special approval and several structural reviews.  

The province introduced its Tall Wood Initiative in 2019. Local governments were invited to submit an expression of interest to be early adopters of mass timber buildings up to 12 storeys ahead of changes to the National Building Code. They were the first province in the country to allow mass timber construction at that height. 

Today a total of 22 communities can build mass timber buildings up to 12 storeys, including the City of Vancouver, which has similar provisions to those of the Mass Timber Initiative in its own building bylaw.

The proposed changes also come on the heels of the largest, most comprehensive mass timber fire testing in Canadian history.

Dubbed The Mass Timber Demonstration Fire Test Program, the national study looked at five scenarios using a two-storey, 334 square-metre mass timber structure.

The study suggests, even in the most severe instances, taller mass timber structures can provide a level of fire performance that is on par with similar concrete and steel-constructed buildings. The testing was observed by more than 150 experts from across Canada.