Canadian building code question

What are the building code requirements for carbon monoxide detectors in Canada?

Carbon monoxide detectors are generally required near sleeping areas in buildings with fuel-burning appliances or attached garages, but exact placement rules and detector types vary by province and building use.

CO detector requirements in Canada depend on whether the building contains a fuel-burning appliance, an attached garage, or both. The National Building Code sets a baseline, but provinces like Ontario have added more prescriptive placement and interconnection rules. Getting this wrong can create a life-safety gap that a permit review will catch.

What to check first

  • Determine whether the building has any fuel-burning appliance, fireplace, or attached garage that triggers a CO alarm requirement.
  • Check the applicable provincial code for placement rules, including which floors and how close to sleeping areas the detectors must be installed.
  • Confirm whether interconnected or combination smoke/CO alarms are required or accepted in the jurisdiction.

Jurisdiction notes

National baseline

The NBC requires CO alarms in dwelling units containing fuel-burning appliances or served by attached storage garages, installed near sleeping areas.

Ontario specifics

Ontario mandates CO alarms on every storey and near all sleeping areas in residential occupancies with fuel-burning appliances or attached garages, with specific interconnection requirements.

Provincial variation

Some provinces require CO alarms in all residential buildings regardless of fuel source. Always confirm the local adoption before relying on the NBC baseline alone.

Work through it in this order

  1. Identify every fuel-burning appliance and attached garage in the building.
  2. Determine which floors contain sleeping areas relative to those sources.
  3. Review the provincial code adoption for CO alarm placement, type, and interconnection requirements.
  4. Document the alarm locations on the life-safety drawing for permit submission.

Common questions

Are CO detectors required in buildings without gas appliances?

Not under the NBC baseline. However, an attached garage or certain provincial rules can still trigger the requirement even without gas service.

Can I use a combination smoke and CO alarm?

Many jurisdictions accept combination alarms, but check whether the local code requires separate devices or specific listing standards.

Do commercial buildings need CO detectors?

CO detection requirements for non-residential occupancies depend on the presence of enclosed parking and mechanical ventilation provisions. Check Part 6 and provincial amendments.