Taller timber buildings up to 18 storeys green-lighted in Vancouver

Policy for taller mass-timber buildings up to 18 storeys green-lighted in Vancouver

2016 construction of UBC Brock Commons' Tallwood Residence. (UBC)

Even taller encapsulated mass-timber buildings can soon be constructed within the City of Vancouver following a swift unanimous decision by City Council on Tuesday.

Such structures will be able to reach a height of up to 18 storeys for residential and commercial uses.

As well, this typology will be permitted for low- and medium-hazard industrial uses, school buildings, and care facilities.

Following this approval, City staff will create the necessary bylaw changes.

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This follows the provincial government’s enactment of similar policies in April 2024, enabling encapsulated mass-timber buildings up to 18 storeys, which was a direction first announced in late 2023.

The provincial changes relate to amending the BC Building Code governing BC municipalities, while the changes approved this week relate to amendments to the separate Vancouver Building Code. Similar policy changes are also expected in Ontario, Quebec, and for the National Building Code.

“These changes will help reduce carbon pollution, support the forestry sector, create jobs, build more homes and lead to more vibrant communities,” said Ravi Kahlon, BC Minister of Housing, in a statement earlier this spring. “We know mass timber looks great, and now we can use it in larger buildings and more types of buildings.”

The new 18-storey limit is up from the previous limit of 12 storeys, which was enacted by the provincial government in 2019 and the municipal government in 2020. Over the prior decade, since 2009/2010, the limit for woodframe construction was up to six storeys.

However, although the regulations have enabled taller mass-timber buildings for years, there have been relatively few proposals and advancements toward construction.

The tallest mass-timber building is still the 18-storey Tallwood House student residence at UBC Brock Commons, which was built in 2017 as a pilot project for research and analysis — the basis of the various new policies enabling taller structures of such materials and construction methods.

Some of the established benefits of mass-timber construction entail not only its significantly lower emissions compared to conventional concrete and steel materials but also the energy efficiency from wood having a greater thermal resistance than concrete and steel. According to City staff, this is why almost all Passive House building projects in Vancouver to date are wood-frame or mass timber.

Mass-timber buildings are also pre-fabricated off-site, which allows a faster construction timeline compared to conventional methods.

Fire safety is one of the most frequently stated concerns relating to allowing taller mass-timber buildings. However, according to researchers, the material of “dense wood construction is inherently fire-resistant,” and “encapsulated” mass-timber designs are buildings where the mass-timber components of the structure have been surrounded by fire-resistant material.

When it comes to seismic resilience, the light weight of mass timber compared to concrete is easier and more cost-effective to design a structure to a higher seismic standard. As well, the modular components of a mass-timber building can be easier to repair after a strong earthquake.

To date, taller mass-timber building designs in BC have often used a hybrid design that incorporates a concrete base — often up to the second level — and a concrete core that serves to not only conceal elevator shafts and exit stairwells but also for added fire protection and seismic resilience. UBC’s Tallwood House uses such a hybrid design.

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