Smoke & CO Alarm Placement in Canada: Where They Go and Which Type to Buy
Smoke alarms go on every storey and outside sleeping areas; CO alarms go near sleeping areas in homes with fuel-burning appliances or attached garages. Here's the placement map, the law in plain language, and how to choose between hardwired, battery, and 10-year sealed units.
In Ontario, working smoke alarms are required on every storey and outside all sleeping areas, and CO alarms are required near sleeping areas in homes with a fuel-burning appliance, fireplace, or attached garage. Other provinces have similar requirements with local variations. Replace alarms by the date printed on the unit — typically 10 years for smoke alarms.
The placement map
| Location | Smoke alarm | CO alarm |
|---|---|---|
| Every storey (including basement) | ✅ Required (ON) | If fuel appliance/garage on that level* |
| Outside each sleeping area (hallway) | ✅ Required | ✅ Required* (adjacent to sleeping areas) |
| Inside each bedroom | Recommended (required in newer construction)** | Recommended |
| Living areas | Recommended | Recommended near fuel appliances |
| Kitchen | Near, not in (10+ ft from cooking to cut nuisance alarms; photoelectric or hush-feature units help) | — |
| Furnace/utility room | Near | Near fuel-burning equipment |
| Attached garage | — | In adjoining living space, not in the garage itself |
Mounting: smoke rises — ceiling mount is preferred, or high on the wall per the manufacturer's instructions. Keep clear of corners, HVAC vents, fans, and windows. CO mixes with air rather than rising sharply, so CO alarms can be mounted at a range of heights — follow the unit's manual.
Hardwired, battery, or 10-year sealed?
| Type | Pros | Cons | Best for |
|---|---|---|---|
| Hardwired + battery backup | Interconnects (all sound together); no dead-battery risk while powered | Electrician to add new locations | New builds, renos, replacing existing hardwired |
| 10-year sealed battery | No battery changes, ever; tamper-proof; cheap to deploy | Whole unit replaced at end of life | Retrofits, rentals, cottages |
| Wireless-interconnect battery | Interconnection without wiring | Premium price | Adding coverage to older homes |
| Standard battery | Cheapest | The 2 a.m. chirp; batteries get borrowed | Last resort |
Interconnection is the feature that saves lives at night — a basement fire triggers the alarm outside your bedroom. If your home is already hardwired, replace like-for-like (note the brand: interconnect signals are brand-specific, and a mixed chain may not talk to each other). If not, wireless-interconnect units — like the Kidde wireless series Maple stocks — add the same protection without opening walls.
Browse smoke & CO alarms and Kidde — authorized-reseller stock, which matters for safety devices: genuine units, valid warranty, current-generation sensors.
Combination units and special cases
- Combo smoke+CO simplifies hallways outside bedrooms — one unit, both requirements.
- Strobe / talking alarms for hearing-impaired household members (Kidde makes both).
- Photoelectric vs ionization: photoelectric responds better to smouldering fires and resists cooking nuisance trips; many current units are photoelectric or dual-sensor. Near kitchens, photoelectric or a hush button is the practical choice.
- Rental properties (ON): landlords must provide and maintain alarms; tenants must not disable them.
Replacement and testing (the part everyone skips)
- Test monthly (the button).
- Replace smoke alarms every 10 years — or by the replace-by date stamped on the back. CO alarms typically run 7–10 years depending on model.
- After any real fire/CO event, replace the unit regardless of age.
- Vacuum dust from grilles annually — dust causes both nuisance alarms and missed alarms.
If your alarms predate your smartphone, they're due.
Common placement mistakes
- Smoke alarm in the kitchen (nuisance trips → unit gets unplugged → no protection)
- No alarm in the basement (where furnace, dryer, and panel live)
- CO alarm in the garage instead of the house side of the door
- Mixing interconnect brands that can't hear each other
- Painting over alarms (yes, it happens; yes, it blinds them)
- "It chirped, so I took the battery out" — the most dangerous sentence in home safety
Frequently asked questions
How many smoke alarms does my house need?
Minimum: one per storey + outside each sleeping area (ON). A typical 2-storey + basement home with bedrooms upstairs = 3 minimum, and more is better (bedrooms, basement).
Do I need a CO alarm if everything in my house is electric?
If there's no fuel-burning appliance, no fireplace, and no attached garage, CO requirements generally don't apply — but check your local rules. Most homes have at least one CO source.
Can I replace a hardwired alarm myself?
Like-for-like swaps on existing wiring are commonly done by homeowners (power off, same base/brand); adding new hardwired locations is electrical work — ESA notification in Ontario, licensed contractor in Quebec. When in doubt, ask.
Are 10-year sealed alarms actually better?
For most retrofits, yes — the failure mode they eliminate (dead/removed battery) is the most common one in real fires.
Why does my alarm chirp every 30 seconds?
Low battery or end-of-life. Check the replace-by date — if it's past, replace the unit, not the battery.
Smoke alarm vs heat alarm — what about the garage/attic?
Garages and dusty/cold spaces often suit heat alarms (no nuisance trips from exhaust/dust). They complement, not replace, smoke alarms in living space.
- Ontario — smoke & CO alarm requirements (Office of the Fire Marshal): ontario.ca
- Kidde Canada — product manuals & placement guidance: kidde.com
- Régie du bâtiment du Québec / municipal fire services (QC requirements): rbq.gouv.qc.ca
- CSA Group (alarm certification standards): csagroup.org
Refreshing your alarms? Maple stocks Kidde hardwired, wireless-interconnect, and 10-year sealed units — tell us your floor plan and we'll count them for you. Ask Maple
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