Ontario has joined other provinces in a growing trend to upgrade its building code allowing encapsulated mass timber construction up to 18 storeys tall.
An upgrade in Ontario’s Building Code, which currently permits residential and commercial buildings to use mass timber up to 12 storeys tall, will help build homes faster and reduce long-term construction costs, the province said in announcing the move Monday.
Mass timber is an engineered product made from layers of solid wood connected by glue, nails or wooden dowels. The wood product is covered in a fire-prevention treatment, such as drywall.
It can be used as a substitute for some concrete or steel, but it is mainly used in addition to traditional construction materials, said Anne Koven, executive director from the Mass Timber Institute at the University of Toronto.
“The more structural mass timber we have in higher buildings, the more carbon dioxide we’re absorbing and storing in our buildings. So that’s really, I think, what the driver is for the excitement about mass timber.”
Traditional construction materials such as concrete, steel and aluminum are highly carbon intensive, whereas a natural renewable resource like wood helps reduce carbon emissions by up to 45 per cent.
For example, the 18-storey Brock Commons Tallwood House located at the University of British Columbia stores 1,753 tonnes of carbon dioxide, according to the 2021 State of Mass Timber in Canada report.
The student residence building was completed in July, 2017 and designed by Acton Ostry Architects. It is the tallest building using hybrid mass timber construction in Canada.
Other buildings such as the 14-storey Academic Wood Tower at the University of Toronto and Limberlost Place – a 10-storey building at George Brown College are some of the tallest buildings using mass timber across Canada.
Increasing the building code regulation to 18 storeys will provide an incentive for more architects, engineers and building developers to create structures using mass timber, Ms. Koven said.
“Practically speaking, there aren’t a lot of buildings that have been constructed as mass timber, but there certainly is a lot of excitement about what the market could be for mass timber,” she said.
“It’s a very, very new industry.”
The 2021 State of Mass Timber in Canada report says there are 412 mass timber structures across Canada with 52 under construction and 20 in the early planning stages.
“It’s a product that will help us get more homes built. This is something that’s been used in a lot of other jurisdictions and we’re catching up,” Paul Calandra, Minister of Municipal Affairs and Housing said Monday.
In January, Ontario, B.C. and Quebec participated in a national consultation about amending building code regulations to increase the use of mass timber in taller buildings.
A multiprovince Joint Task Group will report on the findings that will be used to implement this change.
Ontario’s forestry sector produces close to $21-billion in annual revenue and supports more than 142,000 jobs in communities across the province, the provincial release said.
“Our abundant natural resources and highly skilled forestry sector are helping to meet the demand for housing across the province,” Graydon Smith, Minister of Natural Resources and Forestry, said in a news release Monday.
“Advanced wood construction will help bring long-term investments to northern communities that will create new, good-paying jobs while increasing housing supply and supporting Ontario’s largest renewable natural resource sector.”