What is the requirement for smoke detectors in a finished basement with bedrooms?

Smoke detectors are mandatory in finished basements with bedrooms in Ontario, and they must be hardwired with battery backup, interconnected throughout the home, and placed both inside each bedroom and in hallways within 5 meters of bedroom doors.

The Ontario Building Code (OBC) has specific requirements for smoke alarm placement in residential spaces, especially when bedrooms are involved. In your finished basement with bedrooms, you'll need hardwired smoke detectors with battery backup - battery-only units are not sufficient for new construction or major renovations. These detectors must be interconnected so when one alarm sounds, they all sound throughout the entire house.

Placement requirements are critical for both safety and code compliance. You need a smoke detector inside each bedroom, plus additional detectors in hallways or common areas within 5 meters of any bedroom door. If your basement has a large open area, you may need additional detectors to ensure no point is more than 9 meters from a smoke alarm. The detectors should be mounted on the ceiling at least 4 inches from any wall, or on walls between 4-12 inches from the ceiling.

Installation must be done by a licensed electrician and requires an Electrical Safety Authority (ESA) permit in Ontario. This isn't a DIY project - the interconnected wiring needs to tie into your home's electrical panel and connect with existing smoke detectors upstairs. The electrician will also ensure proper placement meets OBC requirements and that the system includes the required battery backup functionality.

For basement bedrooms, you'll also need carbon monoxide detectors if you have fuel-burning appliances (furnace, water heater, fireplace) or an attached garage. These should be placed outside sleeping areas and can be combination smoke/CO units to reduce the number of devices on your ceiling.

During your building permit application for the basement finishing, the City of Ottawa will review your smoke detection plan as part of the electrical drawings. The electrical inspector will verify proper installation before issuing occupancy approval. Expect this electrical work to cost $800-1,500 depending on the number of detectors needed and complexity of running new wiring.

If you're converting your basement into a secondary dwelling unit, additional fire separation requirements apply, including potential need for separate smoke detection systems and enhanced fire-rated assemblies between units.

For a free consultation on your basement bedroom project including all code compliance requirements, contact Ottawa Basements. We coordinate with licensed electricians to ensure your finished basement meets all Ontario safety standards.