The Ontario Building Code | Interconnection of Smoke Alarms
9.10.19.5. Interconnection of Smoke Alarms
(1) Where more than one smoke alarm is required in a dwelling unit, the smoke alarmsshall be wireref ="http://thehandyforce.com/electrical/" title ="Electricians in East York">wired so that the activation of one alarm will cause all alarms within the dwelling unit to sound.
In Plain Language
Smoke alarms within a dwelling unit or between certain units must be interconnected as set out in this article, so if one alarm detects smoke, all of them sound together.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.