Adapting Canada’s Building Codes for a Changing Climate

In addition to meeting public safety objectives, building codes are meant to ensure that structures can stand up to the conditions they’re likely to face over time – including extreme events like hurricanes and earthquakes. 

Climate change is altering the climatic conditions that buildings across Canada will need to withstand in the decades ahead. The National Research Council of Canada, in with funding support from Infrastructure Canada, is responding to this reality by preparing design guidance, which considers climate change, for potential inclusion in upcoming editions of the National Building Code of Canada (NBC). RWDI has been awarded an important contract for work to inform this effort, especially in the areas of wind and snow loading. 

This isn’t the first time RWDI experts have supported the development of Canada’s building codes. The existing NBC relies on estimates and analysis our team delivered in the early 1990s. RWDI founder Peter Irwin has frequently been called to serve on code committees, contributing his wind and snow engineering insights to the development and refinement of official standards and guidelines over many decades.

But the work we’ll carry out over the next several years is new in several respects. For instance, we’re charged with exploring options and proposing changes to the NBC’s design for wind loads and snow loads: we’ll develop a path forward for the implementation of a uniform risk approach, as opposed to the uniform hazard approach currently in use. Experts believe that adopting a uniform risk approach would put the NBC in a better position to account for climate change – even if we can’t know today precisely how risks will evolve in the future. 

We’re also working with partners at Western University, the University of Waterloo, and Applied Research Associates to address regional variations in wind and snow design values. Canada’s regions have always experienced varied climatic conditions – but what’s new today is that climate change is affecting the country’s regions in different ways and at different rates. Our in-house climate experts and our external partners will combine their complementary insights on climate data analysis to craft appropriate design guidance for Canadian buildings and structures from coast to coast to coast.

In addition to those key tasks, we’ll also: 

• Establish snow load factors for diverse building shapes (and, again, for various regional conditions). 
• Use statistics drawn from extreme value distributions of reference wind pressures and ground snow loads to assess how changes in the frequency and severity of those events should inform the code requirements. We’re working with our partners at the University of Waterloo to carry out some of the specialized statistical analysis that will be part of this work.
• Develop climatologies that incorporate winds from hurricanes and tornados, work that will be led by our partners at Applied Research Associates.
• Identify potential changes to reliability targets, assumed building service life and return periods for design, all based on a changing climate. 

Our team looks forward to working with the National Research Council and Infrastructure Canada, our external partners and with fellow engineers in every part of this process. RWDI embraces this opportunity to share our wind, snow and climate expertise in a way that will promote the safety and performance of buildings across Canada for many years to come.