Ontario building code question

What are the Ontario Building Code requirements for fire separations?

Ontario adopts fire separation requirements through its own Ontario Building Code, which is based on the NBC but includes province-specific amendments affecting ratings, exemptions, and construction types.

Fire separation requirements in Ontario follow the OBC rather than the NBC directly. While the baseline provisions are similar, Ontario amendments can change fire-resistance ratings, exemption thresholds, and how certain occupancy combinations are treated. The safest approach is to confirm the OBC edition in force for your permit, then verify how it adopts or modifies the relevant NBC fire separation clauses.

What to check first

  • Ontario publishes its own building code rather than adopting the NBC directly, so always reference the OBC edition applicable to your permit.
  • Fire separation requirements can differ from the NBC in rating thresholds, exemptions for sprinklered buildings, and treatment of specific occupancy combinations.
  • Confirm the OBC amendment status and any supplementary standards referenced before finalizing fire separation details on a project.

Jurisdiction notes

Ontario's own code

Ontario maintains the Ontario Building Code (OBC) as a standalone regulation under the Building Code Act. It is based on the NBC but includes Ontario-specific amendments.

Edition and amendment timing

Verify which OBC edition applies to your building permit application, as amendment cycles do not always align with NBC publication dates.

Supplementary standards

The OBC references supplementary standards (SB series) that can affect fire separation design, energy performance, and other requirements.

Work through it in this order

  1. Identify the applicable OBC edition and confirm the permit application date.
  2. Locate the fire separation provisions in the OBC for your building's occupancy, height, and construction type.
  3. Compare with the NBC baseline if working across jurisdictions or referencing national guidance documents.
  4. Document the specific OBC clauses and any referenced supplementary standards that govern the fire separation design.

Common questions

Is the Ontario Building Code the same as the National Building Code?

No. Ontario publishes its own building code under the Building Code Act. While it is based on the NBC, it includes province-specific amendments and supplementary standards.

Can I use NBC fire separation tables directly for an Ontario project?

Not without verifying the OBC amendments. Ontario may modify ratings, add exemptions, or reference different standards for the same building condition.

Where do I find the supplementary standards referenced by the OBC?

Supplementary standards (SB-1 through SB-13) are published alongside the OBC and cover topics from energy performance to fire protection.