Taller wood condos may lower costs
Building code changes are examined
Calgary builders are keeping a close eye on possible changes to building codes allowing taller condo buildings made of wood — which could lower construction costs and boost affordability for buyers. “There is definitely a market for affordable apartment product in Calgary, particularly in the inner city,” says Doug Owens, general manager of multifamily for Brookfield Homes. “If construction costs are truly 25 per cent less than concrete and steel construction, this would represent a substantial improvement in affordability.”
The national building code currently only allows buildings of up to four storeys to be made of wood frames due to fire safety concerns.
Anything higher must be framed with non-combustible materials such as steel or concrete. But proposed changes to the code would allow woodframe buildings of up to six storeys, or 18 metres.
Introducing mid-rise, wood-frame residential and mixed-use structures would create “a new level of affordability in Calgary” for condo apartments, says Owens.
Calgary builders and developers gathered recently to learn about proposed changes to the national building code — and what B.C.’s experience has been building the new form, which it introduced in 2009.
Hosted by the Canadian Home Builders’ Association-Alberta, the session also included the City of Calgary’s take on the idea of introducing such buildings to the residential mix.
The benefits of changing the code include better affordability for buyers, quicker construction for developers and lowered construction costs, said the presenters.
Wood-frame, mid-rise construction saves about 25 per cent compared to steel-frame buildings and 30 per cent compared to concrete construction, said Sukh Johal, technical adviser with WoodWorks B.C. — a project of the Canadian Wood Council that seeks to increase the use of wood in construction.
When architect Vivek Menon was working on a mid-rise, wood-frame project in Kamloops, he found a 50 per cent increase in yield, with a 30 per cent savings in building costs.
Tradespeople were easier to find for timber construction — and with the shorter delivery time, there were less carrying and insurance costs, he said.
The upper floors sold first and at a premium, while the middle floors took longer to sell.
In B.C. and other earthquakeprone areas, the increased flexibility of the structures means they withstand seismic activity well. A seven-storey building — six floors of wood above one steel level — was constructed and successfully withstood a shake-table test in Japan in 2009.
Research is also being conducted by the National Research Council and various affiliated groups on other areas of concern particular to the construction material, said Ineke Van Zeeland, manager of codes and standards for Canadian Wood Council.
Managing sound transfer, protecting the taller building envelope from increased wind and weather — and not the least, ensuring fire protection during construction and habitation — are important research topics.
Although the national code is regularly revised, it is each provincial government that has the responsibility over construction through its own provincial building codes.
The proposed changes to the national code will go to public consultation, likely in the fall. The earliest they could be passed would be in 2015 — and it often takes a further year for national code changes to be adopted by the provinces.
While places such as Vancouver, Winnipeg and Toronto still have mid-rise, wood-frame buildings that were constructed in the late 19th and early 20th centuries before lower thresholds were established, it wasn’t until 2009 that B.C. fast-tracked a change in its building code to allow wood-frame residential construction to six storeys, or 18 metres, from a height of four storeys.
Since then, many B.C. builders have taken up the new form. So far, 130 projects have been proposed under the new regulations, with 61 per cent in the lower mainland and another 26 per cent on Vancouver Island.
It’s important to note there are different concerns when building mid-rise compared to walk-up buildings, Johal said.
“Is six storeys the same as a three-storey times two? It looks the same, but it’s not,” said Johal.
An integrated design team is needed from the beginning, he said, adding sprinkler systems are installed at the front end, not near the end of construction. Deck framing is also affected, as is stud spacing and the placement of firewalls.
Building taller with wood means that other construction materials need to be as similar as possible because wood shrinks up to 10 centimetres in mid-rise buildings in the months after construc-
Claire Young’s column
F11 tion. “Shrinkage is the biggest issue,” said Johal. “We recommend factory-built, pre-fabricated panels.”
This also reduces the amount of weather exposure such materials receive on site.
Dave Turnbull, product development manager for Landmark Group, attended the same CHBA session when it was held in Edmonton. He said Landmark is interested in pursuing mid-rise, wood-frame construction — in part because the company has a plant to pre-fabricate construction panels.
“It fills a niche,” said Turnbull.
“There’s definitely an affordability story to this. I think with the experience in B.C., there have been a lot of lessons learned. We’ll probably look at doing this.”
Because Landmark has built walk-up, four-storey buildings as well as highrises in Edmonton, the company would look at launching a mid-rise there first.
“That’s also where we have our panelization plant,” said Turnbull.
“We build all of our homes in Edmonton through that panelization plant. There are some real advantages to doing this with a panelization plant rather than having everything exposed to the elements. It goes quite a bit quicker, so you have less exposure to vandalism and arson.”
While it will be a few years before mid-rise, wood-frame buildings could be seen in Calgary as a regular form, the city is interested in fasttracking demonstration projects in the meantime as an “alternative solution.”
“As long as we meet the intents of the code, we’re able to look at various options. We can see a model of what is possible at the national level and we can look to build on that here in Alberta and in Calgary,” said Kevin Griffiths of the city's development and building approvals department.
“We’re open today to sitting down and discussing what’s possible.”
An artist’s rendering of a possible 10-storey version of the Wood Innovation and Design Centre in Prince George, B.C. — expected to be the tallest wood building in North America and possibly the world.