NBC 2025 Stairway Design and Dimensions: A Guide by Your London, Ontario Construction Contractor
Sarah's Expert Insight
Senior Consultant at empcontracting.ca Inc.
"In London, Ontario, stairway non-compliance is one of the most common reasons for failed building inspections during residential renovations. At empcontracting.ca Inc., we emphasize that getting the rise and run correct during the framing stage is vital, as even a 5mm deviation can pose a significant safety risk and lead to costly retrofits to meet NBC 2025 standards."
Essential Stairway Standards under NBC 2025
Designing compliant stairways is critical for safety and accessibility in any residential or commercial project. As empcontracting.ca Inc. your construction contractor in London, Ontario, we ensure that every staircase meets the rigorous standards of the National Building Code of Canada (NBC) 2025 to ensure both legal compliance and user safety.
Rise, Run, and Tread Dimensions
The NBC 2025 specifies strict tolerances for rise and run to prevent tripping hazards. For private stairs within a dwelling unit, the maximum rise is 200 mm, while the minimum run is 255 mm. Consistency is mandatory; the code requires that the dimensions of all treads and risers in a single flight remain uniform, with very narrow tolerances permitted between adjacent steps.
Minimum Width and Headroom Requirements
To facilitate safe passage and emergency egress, the NBC 2025 mandates a minimum clear width for stairs, generally 860 mm for stairs serving a single dwelling unit. Furthermore, a minimum headroom clearance of 2,050 mm must be maintained throughout the stairway and over all landings to prevent injury and accommodate various user heights.
Landings, Handrails, and Guards
Landings are required at the top and bottom of every flight of stairs to provide a stable resting point and break up long vertical climbs. Additionally, handrails must be installed at a height between 865 mm and 1,070 mm. These must be ergonomically designed for a firm grip and remain continuous for the entire length of the flight. Guards are also required where there is a vertical drop of more than 600 mm to protect occupants from falls.