National baseline
The NBC specifies minimum illumination levels for stairways and requires emergency lighting in exit stairs. The lighting must be maintained at the tread surface during both normal and emergency conditions.
Canadian building code question
What are the building code requirements for stairway lighting in Canada?
Stairways must be illuminated to minimum lux levels at the treads, with exit stairs requiring emergency lighting backup. The lighting requirements depend on whether the stair is an exit stair, a public corridor stair, or a private stair within a dwelling unit.
Stairway lighting requirements in the Canadian building code address both normal illumination levels and emergency backup. Exit stairs have the strictest requirements because they serve life safety during evacuation. The code specifies minimum illumination at the tread surface, emergency power backup duration, and switching requirements that prevent occupants from being left in the dark.
What to check first
- Determine whether the stairway is an exit stair, a public stair, or a private residential stair, as lighting requirements differ for each.
- Check the minimum illumination level required at the tread surface for the stair type.
- Verify emergency lighting requirements including backup power duration and the areas that must be illuminated during a power failure.
Jurisdiction notes
Exit stair specifics
Exit stairs require emergency lighting that activates automatically upon power failure and provides illumination for a minimum duration specified in the code.
Residential exemptions
Private stairs within individual dwelling units have less prescriptive lighting requirements than exit stairs or public corridor stairs.
Work through it in this order
- Classify the stairway as an exit stair, public stair, or private residential stair.
- Determine the minimum illumination level required at the tread surface for the applicable stair classification.
- Specify emergency lighting to meet the backup power duration and illumination requirements for exit stairs.
- Confirm switching requirements to ensure stairway lights cannot be inadvertently turned off by occupants.
Common questions
What is the minimum lighting level for an exit stair?
The NBC specifies a minimum illumination level at the tread surface. The exact value depends on the code edition and stair type. Check the lighting section of Part 3 for the applicable requirement.
How long must emergency lighting last in a stairwell?
The NBC requires emergency lighting to provide minimum illumination for a specified duration after power failure. The standard duration is typically 30 minutes to 2 hours depending on building type.
Do residential stairs need emergency lighting?
Private stairs within a dwelling unit generally do not require emergency lighting. Common stairs serving multiple units in a residential building do require emergency lighting as part of the exit system.