Canadian Contractor

By Richard Lyall   

Its time to update the code: Lyall

Canadian Contractor codes nbc Richard Lyall

Times are changing quickly in the residential construction world due to advances in building technology. The regulations that govern the industry must also be tweaked to reflect this new reality.

The battle over the number of stairwells that are needed in mid-rise residential buildings is a case in point. Presently, the National Building Code (NBC) of Canada stipulates that apartment buildings of three or more storeys require two exits. The rule has been in effect since 1941. It made sense back then to provide additional ways of exiting a building in the event of a fire. But today, it’s not logical.

Sprinkler systems and fire suppression techniques have advanced considerably since the mid-1900s. We have smoke and heat detectors and many have a direct connection to a central fire alarm or fire department, ensuring a quick response time in the event of an emergency. New materials are also used in walls to slow down the spread of flames and there are spring-loaded doors to cut off smoke.


In many buildings, requiring builders to have two staircases has led to a hotel-style layout with a windowless hallway and apartments lined up on either side and a stairwell at either end.

As part of NBC changes, consideration is being given to allow a single fire exit in buildings six storeys in height as long as there are no more than four dwellings on any storey, the building has sprinklers and a fire alarm system is installed that notifies the fire department if it is triggered.

RESCON supports the single-staircase solution on buildings up to six storeys as it allows for more efficient building floorplates and larger suites.

One stairwell, at least in buildings of up to six storeys, makes perfect sense, as you gain more space per floor. The more affordable that housing is, the more options and types of housing get built.

With more support for missing middle housing, present regulations are just too restrictive. Municipalities like Toronto have taken steps to permit more duplexes, triplexes and fourplexes in residential neighbourhoods and allow residential buildings of up to six storeys along major avenues, the purpose being to allow more missing middle housing and density. Revamping the rules to allow one stairwell instead of two would free up valuable space for larger units and more bedrooms per unit, something we desperately need.

An impact analysis for major streets done by the City of Toronto showed that the savings of the solution is equivalent to one bedroom per storey in a six-storey building. For a six-storey building with four dwellings per storey, and commercial use at grade, the solution creates design flexibility for five more bedrooms.

At a recent Urban Land Institute webinar, a presenter estimated that moving to a single staircase would free up five per cent more usable space per floor within a building, which could add as many as 6,000 additional bedrooms to Toronto mid-rise buildings along major streets over the next 10 years.

However, we are lagging behind.

More permissive building practices that allow single-stair buildings are being adopted in jurisdictions around the world. Countries like Germany, for example, permit single-stair buildings of up to seven storeys.

Seattle has permitted them since 1977 in buildings up to six storeys, with a maximum of four apartments per floor. The state of Washington is looking at whether to expand that state-wide and Virginia is looking at allowing single staircases in buildings up to six storeys instead of the current three.

In California, legislation was passed last year that includes direction to include single-stair designs in updated building standards.

In Canada, B.C. is looking at a change and has hired a consultant to look at the issue of single egress stairs as part of changes to its building code and identify pathways forward.

In Ontario, a Housing Affordability Task Force recommended that the building code and other policies be modernized to remove any barriers to affordable construction, such as allowing single-staircase construction for up to four storeys. So far, though, no action has been taken.

The only country more restrictive than Canada on the issue is Uganda where double staircases are required in any multi-unit buildings over one storey. In Canada, present rules require buildings up to two storeys to have one stairwell provided the total occupant load served by the exit is not more than 60 people.

Clearly, we are behind the times.

As density increases in our cities, the rules and regulations must reflect reality and advancements in technology.

Changing an 83-year-old rule would certainly unlock a lot more housing space in these desperate times and result in more family-friendly housing with additional bedrooms in the buildings. Residential structures that need only a single staircase can also be built on a smaller footprint.

Requiring two staircases only makes the units more expensive. We are behind the times. An adjustment to the present rules is required.

Richard Lyall is president of the Residential Construction Council of Ontario (RESCON). He has represented the building industry in Ontario since 1991. Contact him at


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