Canadian building code question

What are the building code requirements for scissor stairs in Canada?

Scissor stairs — two independent exit stairs sharing a single shaft — are conditionally permitted under the NBC when each stair is separated from the other by a fire separation and the exit independence and travel distance requirements are met as if the stairs were in separate shafts.

Scissor stairs are an efficient way to provide two exits within a compact floor plate, but the code treats them with caution. Each stair must function as an independent exit with its own fire separation, and the shared shaft introduces additional requirements around smoke control, sprinklering, and door locations that vary by province.

What to check first

  • Scissor stairs are two independent exit stairs within a single shaft — each must be separated from the other by a rated fire separation.
  • Exit independence, travel distance, and remote-separation rules apply as if the stairs were in separate locations.
  • Provincial codes may restrict or further condition scissor stair use — always confirm local adoption.

Jurisdiction notes

National baseline

The NBC sets conditions for scissor stairs including fire separation between the two stairs, exit independence, and sprinkler requirements.

Provincial adoption check

Some provinces restrict scissor stairs in certain occupancies or building heights, or add conditions beyond the NBC baseline.

Project-specific variables

Floor plate size, occupancy, building height, and sprinkler status all affect whether scissor stairs are viable and what additional conditions apply.

Work through it in this order

  1. Confirm the building occupancy, height, and floor plate size to determine if scissor stairs are a viable exit strategy.
  2. Review the NBC scissor stair provisions for fire separation, exit independence, and travel distance.
  3. Check sprinkler and smoke control requirements specific to the shared shaft condition.
  4. Verify provincial adoption and any local amendments or restrictions.
  5. Document referenced sections for permit submission and coordination with the exit design.

Common questions

Are scissor stairs allowed in all buildings in Canada?

No. The NBC permits them under specific conditions, and some provinces further restrict their use based on occupancy or building height.

Do scissor stairs count as two separate exits?

Yes, provided each stair meets the exit independence, fire separation, and travel distance requirements as if it were in a separate shaft.

What fire separation is required between the two stairs in a scissor configuration?

The separation must meet the same fire-resistance rating required for exit stair shafts, but the specific rating depends on building height and occupancy.