Building Code Change to allow Single Stair Residential Buildings up to Six Storeys
A Co-signed Letter to the Ontario Association of Architects Housing Affordability Task Force
Ontario architects have come together to write an open letter requesting an update to the building code. They ask that the Canadian Commission on Building and Fire Codes permit a single egress stair for residential buildings up to six storeys.
The proposed change would create the “missing middle” low- to mid-rise housing that many Ontario cities are lacking today. These new buildings would include a limit of four dwelling units per floor and sprinklers as an active fire protection measure. Additional safety requirements of fire separation and positive pressurization in the stairwell would be comparable to other modern design solutions in the rest of the world.
Updating the code to create this missing typology would enable more sustainable urban development by densifying in a way that is attractive, affordable and has low embodied carbon. Adding more of these missing dwellings to our cities will balance the housing supply and ameliorate the Ontario housing crisis.
The letter can be read here.
From the 2008 Senez Reed Calder report on the origins of Canada’s building code, the authors noted that the First Edition of the code was based on 1941 US building standards. They also concluded that today’s limits on building area and height were based on the capability of fire services in the early 1900’s. Much has changed in our construction practice and emergency response since that time, but the building code has not kept up with these differences. The requirement for 2 means of egress is one such practice that remains unchanged.
The proposed code change is comparable to codes in the US. The US building code permits buildings up to 4 storeys with single exit stairs. The city of Seattle which uses similar methods of wood construction permits six. These rules are quite stringent compared to other codes around the world, of which Canada is the most restrictive.
For more information, please read the supporting documentation included at the bottom of the open letter.