Toronto city skyline

World Cities Day 2022 – Protecting Canada’s urban dwellers from extreme weather events

A line of violent windstorms carved a path of destruction through Ontario and Quebec in May of this year, passing close to or directly through three of Canada’s four largest cities: Toronto, Montreal, and Ottawa. And, just weeks ago, Hurricane Fiona devastated Atlantic Canada, wiping out houses and buildings, in Nova Scotia, Prince Edward Island, and Newfoundland. High winds have long posed a risk to people and infrastructure, but that risk is increasing exponentially.

Currently, more than half of the world’s population lives in towns and cities, with this figure expected to reach nearly 70 percent by 2050. In Canada, that number is even more significant. Nearly three in four Canadians, almost 74 percent, live in one of Canada’s larger urban centres as of 2021. With so many people residing in more densely populated areas, extreme weather events put them at greater risk. 

“Extreme wind is a significant driver of disaster losses in Canada,” says Dan Sandink, from the Institute for Catastrophic Loss Reduction (ICLR)—an institute of Western University. “We know that more than 85% of all natural catastrophe events recorded by the Canadian property and casualty insurance industry over the past ten years were partially or fully caused by high winds. We also know that the impact of extreme weather events is rapidly intensifying, and the clock is ticking for meaningful solutions.” 

Standardization is one of the most important of these solutions because it literally affects built environment from the ground up. Standards can be used to improve everything from product development, such as roofing shingles, to installation. Hundreds of standards are referenced in the National Building Code of Canada, which sets out technical provisions for the design and construction of new buildings, as well as alteration and demolition of existing ones, to protect public health and safety by ensuring that homes and buildings are well-made and efficient. 

“Standards are key to advancing industry’s development of resilient homes and buildings,” says Chantal Guay, CEO of the Standards Council of Canada. “Standards are created by experts in the field and interested parties who come together to develop the best version of guidance possible. Shorter timelines and an inclusive process allows standards to be more agile than codes and regulation, making them an excellent complement to keep engineering and construction methods and products efficient, effective, and safe.”

Experience in the Canadian insurance industry indicates that non-engineered, residential structures (e.g., single-family homes) drive most losses during disasters. Damage to residential buildings during extreme wind events, including tornadoes, also creates life safety issues associated with flying debris and building collapse. Significant engineering knowledge exists that can be readily applied to reduce the risk of damage to buildings during high wind events, and this knowledge is used to create standards, such as the newly published CSA S520:22 Design and construction of low-rise residential and small buildings to resist high wind.

Funded by SCC’s Standards to Support Resilience in Infrastructure program, the CSA S520 standard provides a set of commonly acceptable, relatively straightforward, and low-cost wind risk reduction measures that can be incorporated into new single-family home construction as well as to major renovations, to reduce risk to life, health, and property. These measures come from practical experience and input from research, engineering, building and insurance professionals, and may be applicable in many regions of Canada. 

“If I told you that you could build a wood frame home to resist a tornado, you might not believe me,” says Robert J. Jonkman from the Canadian Wood Council who participated in the standard development committee.  “CSA S520 outlines how to build tornado-resistant wood frame houses, highlighting the important connections from roof to foundation. For anyone concerned with building a more resilient home, whether it’s professionals in the building industry, code officials, building material manufacturers, or homeowners, it’s definitely worth the read.”

Relying on standards like CSA S520 to construct more resilient buildings aligns well with the theme of World Cities Day, October 31 “Act Local to Go Global,” and of the United Nations Sustainable Development Goal 11, to make cities and human settlements inclusive, safe, resilient and sustainable.  The theme focuses on bringing together different partners and diverse stakeholders to share their experiences and approaches to local action to empower governments to create greener, more equitable and sustainable cities. At a global level, using standards as a way to measure progress is possible through the ISO 37120 Series on City Data. The series, championed by Canada, includes ISO 37123 - Indicators for Resilient Cities. These standards provide a method to collect meaningful data that can be compared to other cities around the world.

As governments work together to modernize our codes to ensure that Canada’s built environment continues to be safe, leveraging standards provides an excellent opportunity to bring in more resilient approaches to issues like high wind safety and other extreme weather events. Using tools like standards, that already at our disposal, brings a more resilient future one step closer.