Code Library › Volume 1 › Section 3.2 — Building Fire Safety
PART 3 — FIRE PROTECTION, OCCUPANT SAFETY AND ACCESSIBILITYUpdated for the 2024 Ontario Building Code

3.2.4.21.Residential Fire Warning Systems

(1) Except where a fire alarm system is installed or required in a building, smoke detectors forming part of a residential fire warning system installed in conformance with CAN/ULC-S540, “Standard for Residential Fire and Life Safety Warning Systems: Installation, Inspection, Testing and Maintenance,” are permitted to be installed in lieu of all smoke alarms required by Article 3.2.4.20., provided that the system is (a) capable of sounding audible signals in accordance with Sentences 3.2.4.20.(12) and (16), (b) provided with a visual signalling component in accordance with Sentences 3.2.4.22.(17) to (19), (c) powered in accordance with Sentence 3.2.4.20.(9), and (d) provided with a silencing device in accordance with Sentences 3.2.4.20.(14) and (15).
← Previous3.2.4.20. Smoke AlarmsNext →3.2.4.22. Two-Way Voice Communication Systems

Common questions about this part of the code

When is noncombustible construction required under the Ontario Building Code?When are automatic sprinklers required in a building in Ontario?What are the fire department access route requirements under the Ontario Building Code?When is a fire alarm system required in a building in Ontario?

Understand this provision in seconds

BUILDAiD Assist explains any article of the building code in plain English — with exact citations, exceptions and related requirements.

Try BUILDAiD Beta

Code text is reproduced for reference from the Ontario Building Code (O. Reg. 163/24, 2024 Building Code Compendium). This page is provided for general information and is not an official copy. Always verify requirements against the official Ontario Building Code and confirm with your local building department.