Do Ontario Homes Need Carbon Monoxide Alarms on Every Floor?
June 15, 2026
This one came from a fresh multi-platform sweep of recent Ontario discussions.
The repeated question was basically this:
Does Ontario now require a carbon monoxide alarm on every floor of a home, even if that floor does not have a bedroom?
The short answer is:
No, Ontario did not create a blanket rule that every floor of every home must have a carbon monoxide alarm. But where Section 2.16 applies, the Code can require alarms not only beside sleeping areas, but also on storeys without sleeping areas.
But the better answer is a little more precise than the social-media versions.
What actually triggers the rule
The every-storey requirement does not mean every home in Ontario suddenly needs a carbon monoxide alarm for no reason.
Section 2.16.1.1. tells you when the carbon monoxide alarm section applies. In practical terms, it applies to buildings containing residential or care occupancy where there is a relevant carbon monoxide source risk, including things like:
- a fuel-burning appliance
- a fireplace
- a storage garage
- or, in some buildings, a forced-air fuel-burning appliance serving the residential area
That matters because the right field question is not just, "Do I need one on every floor?"
It is:
If my building falls into the carbon monoxide alarm section, what locations are now mandatory?
Where the Ontario Fire Code now requires them
The key wording is in Article 2.16.2.1.
For a suite with a fuel-burning appliance, flue or fireplace, Sentence 2.16.2.1.(1) requires a carbon monoxide alarm:
- adjacent to each sleeping area in the suite, and
- on each storey without a sleeping area in the suite
That second line is the one many people missed.
So if Section 2.16 applies to that suite, the basement, main floor, or upper level can still need a carbon monoxide alarm even when that level has no sleeping area.
The same pattern shows up again in other trigger situations:
- where the risk comes from a fuel-burning appliance outside the suite but sharing a common wall or floor/ceiling assembly with it: 2.16.2.1.(2)(c)
- where the risk comes from a storage garage sharing a common wall or floor/ceiling assembly with the suite: 2.16.2.1.(3)(b)
- where the suite is directly heated by a forced-air fuel-burning appliance not located in the suite: 2.16.2.1.(4)(d)
So the better answer is not "yes, every floor" and it is not "no, just bedrooms."
It is:
Check whether Section 2.16 applies first. If it does, the required locations can include storeys without sleeping areas.
What this means for highrise residential
This is where a lot of condo and apartment conversations go sideways.
People hear "every floor" and assume the rule only matters in houses with a basement, main floor, and second floor.
But in highrise residential, the issue can still be very real. The difference is that the trigger often comes from the building condition around the suite, not just from a fireplace or appliance inside the suite itself.
For example:
- if the building has a storage garage, suites that share a common wall or common floor/ceiling assembly with that garage can trigger the suite alarm requirements in 2.16.2.1.(3)
- if the building has a fuel-burning appliance outside the suite, suites sharing the relevant common construction can trigger the suite alarm requirements in 2.16.2.1.(2)
- if a forced-air fuel-burning appliance directly heats the residential area, 2.16.2.1.(4) can also trigger alarms in the suite and in the corridor system
That means a highrise owner, condo board, property manager, or landlord should not reduce the issue to:
"There is no furnace inside the unit, so the suite is fine."
That can be a weak answer if the real carbon monoxide source risk is elsewhere in the building.
There is also an added highrise detail in 2.16.2.1.(4)(b):
Where a forced-air fuel-burning appliance directly heats the building, carbon monoxide alarms may also be required in public corridors serving suites of residential occupancy, with spacing rules for those corridors.
So in a highrise, the review should usually split into two separate questions:
- what does the suite itself require?
- what does the shared building or corridor condition require?
That is often the practical difference between a detached-house conversation and a highrise residential one.
What this means in plain language
If your house, townhouse, condo unit, apartment, or rental suite falls under the carbon monoxide alarm section because of one of the listed source conditions, the Code is no longer focused only on the bedroom area.
It now also looks at whether there are storeys without sleeping areas that still need alarm coverage.
That is why recent discussion started using plain-language summaries like "every floor," but that phrase is too blunt on its own.
The safer way to say it is:
- adjacent to sleeping areas
- and on storeys without sleeping areas
but only in the situations the Code actually describes.
The part owners and landlords should not miss
The installation rule is only part of the job.
The Fire Code also assigns ongoing duties:
- 6.3.4.3.(1) says carbon monoxide alarms must be maintained in operating condition
- 6.3.4.4. says the landlord of each rental suite of residential occupancy must give the tenant the manufacturer's maintenance instructions or approved alternative instructions
- 6.3.4.8.(2) says landlords must test carbon monoxide alarms annually, after every change in tenancy or residents, and after certain electrical-circuit changes
So for rental buildings, the real compliance question is not just "Did we install alarms?"
It is also:
- Are they still operating?
- Were they placed in the now-required locations?
- Are they being tested on the required schedule?
What people get wrong
There are three weak answers showing up in current discussion:
- "Ontario now requires a carbon monoxide alarm in literally every home on every floor."
- "The rule only applies near bedrooms, same as before."
- "If the basement has no bedroom, it does not need a carbon monoxide alarm."
Those are all too loose.
The better reading is:
- first check whether the suite or building is actually caught by Section 2.16
- then apply the location rule in 2.16.2.1
- and then remember that the Code can reach storeys without sleeping areas in those situations
What to check in the field
If you are reviewing a home, rental unit, or multi-unit building, the practical checklist is short:
- Is there a fuel-burning appliance, flue, fireplace, storage garage, or forced-air fuel-burning system that triggers the section?
- Are the required alarms located adjacent to sleeping areas?
- Is there an alarm on each storey without a sleeping area where the Code requires it?
- In a highrise residential building, is the source risk inside the suite, elsewhere in the building, or tied to a storage garage or shared mechanical system?
- If the building is directly heated by a forced-air fuel-burning appliance, do the public corridors also need carbon monoxide alarms under 2.16.2.1.(4)(b)?
- In a rental suite, is the landlord handling the maintenance instructions and testing duties properly?
- If a device has been replaced, does the replacement still comply with the current Fire Code requirements?
That last point matters because 6.3.4.7.(5) says that when a carbon monoxide alarm required by Subsection 2.16.2. is replaced, the replacement has to conform to Article 2.16.2.1.
The one-line takeaway
If you only remember one thing, remember this:
Ontario did not create a blanket "every floor of every home" carbon monoxide alarm rule. The right reading is: check whether Section 2.16 applies, then install alarms in the locations it actually names, which can include storeys without sleeping areas.
References
- Ontario Fire Code 2026, 2.16.1.1. — application of the carbon monoxide alarm section
- Ontario Fire Code 2026, 2.16.2.1.(1) — adjacent to each sleeping area and on each storey without a sleeping area where a fuel-burning appliance, flue or fireplace is installed in the suite
- Ontario Fire Code 2026, 2.16.2.1.(2)(c) — every-storey requirement where the source is outside the suite but shares common construction with it
- Ontario Fire Code 2026, 2.16.2.1.(3)(b) — every-storey requirement where the suite shares common construction with a storage garage
- Ontario Fire Code 2026, 2.16.2.1.(4)(d) — every-storey requirement where the suite is directly heated by a forced-air fuel-burning appliance
- Ontario Fire Code 2026, 2.16.2.1.(4)(b) — corridor alarm requirements where public corridors serving suites are directly heated by the forced-air fuel-burning appliance
- Ontario Fire Code 2026, 6.3.4.3.(1) — carbon monoxide alarms to be maintained in operating condition
- Ontario Fire Code 2026, 6.3.4.4. — landlord to provide maintenance instructions
- Ontario Fire Code 2026, 6.3.4.7.(5) — replacement alarms required by Subsection 2.16.2 must conform to Article 2.16.2.1
- Ontario Fire Code 2026, 6.3.4.8.(2) — landlord testing duties