What is the minimum width of a basement staircase in Ottawa?

The minimum width for a basement staircase in Ottawa is 860mm (approximately 34 inches) according to the Ontario Building Code, which governs all residential construction in the city.

This width requirement applies to the clear, unobstructed space between handrails or between a handrail and the opposite wall. The measurement is taken at the narrowest point of the staircase, ensuring there's adequate space for safe passage and emergency egress. This is particularly important for basement stairs since they often serve as a primary exit route from below-grade living spaces.

Additional staircase requirements that often go hand-in-hand with the width specification include a minimum headroom of 1950mm (76.8 inches), maximum riser height of 200mm (7.9 inches), and minimum tread depth of 210mm (8.3 inches). The staircase must also have handrails on at least one side if it has three or more risers, and both sides if the width exceeds 1100mm.

In Ottawa's older homes, many existing basement stairs don't meet current code requirements, having been built to earlier standards. When renovating or finishing a basement, especially for secondary suite conversions, bringing stairs up to current code is often required. This is particularly relevant for homeowners considering secondary dwelling units, where proper egress is critical for occupant safety and rental compliance.

Climate considerations in Ottawa also affect staircase construction. The freeze-thaw cycles can cause settling in older homes, potentially affecting stair alignment and safety. Proper construction with adequate footings below the frost line (4 feet in Ottawa) helps prevent future issues.

If you're planning basement renovations or considering a secondary suite conversion, it's worth having your existing stairs evaluated early in the planning process. Non-compliant stairs can significantly impact project timelines and budgets, as they may require complete reconstruction rather than simple updates.

For specialized basement renovations and staircase upgrades, our dedicated team at OttawaBasements.com has extensive experience bringing older basements up to current Ontario Building Code standards while maximizing functionality and value.