New measures to permit multiple uses in mid-rise wood buildings and to expand structural earthquake resistance are among 600 changes introduced to Canada’s national building codes this year.
The revisions, introduced by the Canadian Commission on Building and Fire Codes under the authority of the National Research Council (NRC), apply to the National Building Code of Canada, National Fire Code of Canada, National Plumbing Code of Canada and National Energy Code of Canada for Buildings.
Formerly the National Model Construction Codes, the regulations are now called Codes Canada.
Codes Canada 2015 was approved earlier this year and unveiled June 28.
Other notable revisions contained in the codes include new design requirements to improve accessibility of stairs and washrooms; significant changes to the run dimension of steps inside houses from the current minimum of 210 millimetres to a new minimum of 254 millimetres; and new requirements to reduce flow rates in showers, to cut water usage.
The new codes are now in effect for federal bodies such as the Department of National Defence and Public Works but at this stage have not yet been adopted by Canada's provinces and territories. Some provinces adhere to the codes closely as they proceed with implementation — generally undertaken by the various jurisdictions in a year to 18 months, explained André Laroche, technical advisor, building regulations, construction for the NRC — but some jurisdictions go their own way with variations reflecting local needs including the demands of local industries or policy-makers.
This has been the case with mid-rise wood buildings, said Laroche, as British Columbia's timber industry has pushed its building code regulators to get out ahead of the national standard. B.C. changed its code to permit six-storey residential wood buildings in 2009, six years before the commission moved on six-storey wood structures in this most recent version of Codes Canada. B.C. already has 250 six-storey wood projects built or underway, said Laroche.
Pierre Gallant, an architect with Morrison Hershfield, based the Burnaby, B.C., who was delegated to speak on behalf of the Royal Architectural Institute of Canada, explained that process.
"B.C. of course has a very large lumber industry so we wanted to use more lumber and reduce carbon footprint so we took the step to achieve that," he said. "And that information through the code commission gets transferred to the national building code, which was updated."
Laroche called the new wood codes a "radical change for sure." Four storeys of wood were permitted in the 2010 version of the national model codes. The Codes Canada 2015 provisions introduce 34 changes to the National Building Code and eight to the National Fire Code including the measures to permit mixed uses.
Ontario waited until the Codes Canada 2015 consultations were well underway to introduce requirements for six-storey wood buildings in January 2015, Laroche said.
Wood buildings of 11 storeys in B.C. and 13 storeys in Quebec were approved after owners proved the designs met the building core requirements through code equivalencies to maintain safety, said Gallant.
The changes to the length of stairs could reduce fall incidents by up to 64 per cent, the NRC said.
Codes Canada 2015 also requires buildings throughout Canada to be designed for earthquake forces regardless of the level of hazard. Laroche said the seismic resilience measures were formulated based on data produced after the New Zealand earthquake of 2011.
Gallant explained, "As you learn more about seismic forces, even though B.C. is obviously on the cusp of the subduction zone (boundaries of tectonic plates), there are significant seismic forces in Ottawa as well. So some of those standards are increased."
Fortier said 90 to 95 per cent of code changes are reactive, responding to submissions from the construction sector or the general public, with the remaining coming from policy-makers such as governments or else identified by the commission as important national or international trends.
Changes to the National Energy Code tend to be in that latter category, said Laroche, with major input from the provinces. Policy goals recently introduced by the Ontario government in its Climate Change Action Plan are not yet reflected in the codes, he said.
"We received recently the provincial government's announced initiatives to welcome climate change adaptability, and we will be shortly launching some working groups trying to address some of the hazards," he said.
New measures for flood plains, flash floods and higher winds would be considered, he said.
As well, Laroche said, "We have taken note of, and we have prepared a policy paper of energy targets, and we share this with the provinces and territories...this is being debated as we speak, and hopefully we should have an outcome in a couple of months so hopefully we can start working and improving energy efficiency for the National Energy Building Code."
Another change that will have a "major, major" impact on builders will be changes to sound transmission within apartments, said Laroche, with new guidelines on acoustics through floors.