Smoke and Carbon Monoxide Alarms: A Plex Owner's Obligations in Québec

ImmoMulti — a direct buyer of income properties on the North Shore — meets plex owners every week who underestimate exactly how far their obligations around smoke and carbon monoxide alarms reach. Yet this is one of the few areas where a simple oversight can be extremely costly: a denied insurance payout, a civil lawsuit, even penal liability after a fire. The basic rule is clear — installation is the landlord's job, routine upkeep is the tenant's — but the nuances (10-year sealed batteries, CO alarms, regulated placement) make all the difference. Here is what every plex owner should verify, sourced directly from Québec authorities.

Who installs and who maintains the alarms in a plex?

The obligation to install and provide smoke alarms falls on the landlord (owner). Routine maintenance — testing the device and replacing the battery when it is weak — falls to the tenant (occupant), except for sealed, non-replaceable batteries. The landlord remains bound to replace a defective or end-of-life alarm.

Responsibility is shared, but it is not symmetrical. As a plex owner, it is up to you to ensure every unit has compliant smoke alarms installed in the right places. The Régie du bâtiment du Québec sets this out in its rental safety advice: the landlord provides and installs the alarms, while the tenant keeps them in working order.

In practice, the tenant must test the alarm (ideally monthly), report any defect, and — for models with a removable battery — replace the battery when it is weak or dead. On your side, you must hand over functional devices at the start of the lease, react quickly to any report, and replace the alarm itself if it is damaged, painted, or past its useful life.

Source: Régie du bâtiment du Québec — Rental safety tips.

What is the 10-year sealed-battery smoke alarm rule?

Over the past few years, several Québec municipalities have tightened their requirements by mandating smoke alarms with a long-life sealed lithium battery, non-removable, lasting about 10 years. The goal is to eliminate the classic silent alarm: the battery removed or never replaced.

In Montréal, by-law RCG 12-003 (amended in 2020) requires this type of alarm in all residential buildings built before 1985 that are not already equipped with electric (hardwired) alarms. More recent buildings are subject to distinct requirements based on their year of construction. As the Association des propriétaires du Québec summarizes:

The key takeaway for owners: a sealed-battery alarm cannot be recharged or repaired. Once it reaches the end of its 10 years (indicated by the manufacturing or replacement date on the casing), it must be replaced in full. That is a plannable expense — not a surprise.

Sources: APQ — Change to smoke alarm regulation on the Island of Montréal; Société d'habitation du Québec — Smoke alarms.

Is a carbon monoxide alarm mandatory in a plex?

Yes. Since April 1, 2019, a carbon monoxide alarm is mandatory in a dwelling if it contains a combustion appliance, or if a wall, floor or ceiling is adjacent to a space housing a combustion appliance or a parking garage. In a plex, the landlord is responsible for providing and installing these alarms.

Carbon monoxide (CO) is an odourless, colourless, and deadly gas. That is why the Government of Québec made a CO alarm mandatory since April 1, 2019 in the dwellings concerned. The rule covers units equipped with a combustion appliance — wood stove, gas fireplace, gas water heater, oil furnace, generator, etc. — but also those where a wall, floor or ceiling is adjacent to a space housing such an appliance or to a parking garage.

For a multi-unit owner, this last point is crucial. A plex with an integrated garage, a shared laundry room housing a gas water heater, or a central boiler room can trigger the obligation to install CO alarms in several units — not only in the one containing the appliance. The alarm must comply with standard CAN/CSA-6.19.

Source: Government of Québec — Carbon monoxide alarms.

Where should you install the alarms in your plex?

Placement is not just a matter of common sense — it is regulated. For the carbon monoxide alarm, the Government of Québec specifies it must be installed on each floor where there is a bedroom and near the bedrooms. Importantly, it must never be placed inside a garage. It is also recommended to keep it at least 2 metres from cooking and combustion appliances to avoid false alarms.

For smoke alarms, the general rule is at least one per floor — including the basement — and near the bedrooms. Because the precise requirements (number, location, battery type) vary from one municipality to another, a plex owner on the North Shore — in Terrebonne, Blainville, Boisbriand or Saint-Eustache — should always confirm their city's fire-safety by-law.

What are the consequences after a fire or claim?

A missing, badly installed, or non-functional alarm can expose the landlord to a refused or reduced insurance payout, civil liability lawsuits from occupants and, in the event of death or injury, penal liability. Documented compliance protects the owner.

This is where the stakes become financial and legal. After a fire or a CO intoxication, the first question asked will be: were the alarms present and functional? Three types of consequences await the negligent owner:

• Insurance: most income-property policies require the owner to maintain compliant safety equipment. A breach can be invoked by the insurer to reduce or refuse the payout following a claim.
• Civil liability: an injured tenant — or a victim's relatives — can sue the landlord for fault, alleging the absence of functional alarms.
• Penal liability and fines: municipal fire-safety by-laws provide for fines for missing or non-compliant alarms; a death or serious injury can lead to heavier penal consequences.

For specific situations — the exact terms of your policy, a contested split of responsibility — consult an insurance broker and, if needed, a lawyer or notary.

Documenting compliance: an asset when you sell

The good news: compliance is cheap and easy to document. Keep a log for each unit of your plex: installation and replacement dates of the alarms, models and standards (ULC, CAN/CSA-6.19), written instructions handed to tenants, and checks performed between tenancies. Keep this file with your other maintenance records.

This log is not only protection against your insurer: it is also a selling point. A multi-unit buyer — or their inspector — will appreciate a building whose fire safety is in order and documented. Conversely, missing or expired alarms found at the pre-purchase inspection can become a point of downward negotiation.

What Québec fire statistics reveal

When people talk about smoke alarms, the temptation is to treat compliance as an administrative formality. The figures from the ministère de la Sécurité publique tell a very different story: in the vast majority of fatal fires, the smoke alarm was absent, disconnected, or out of order. For a plex owner, these numbers are not abstract statistics — they describe precisely the scenario that turns a property loss into a human tragedy and a lawsuit.

According to a ministry study of deaths linked to fires between 2017 and 2021, roughly one building in four hit by a fatal fire had no functional smoke alarm. Put differently, in about three quarters of fatal fires, the alarm was either non-existent, disconnected, or unable to work. The lesson is brutally simple: the device only saves lives if it is present, powered, and operational on the day it must sound.

The statistics on reported fires in 2021 and 2022 point the same way. Of all buildings damaged by fire over those two years, barely more than a third had a smoke alarm that was both present and functional at the time of the fire. The rest — the majority — had a missing or failing device, or none at all.

Why so many silent alarms? The most common causes are well known: a battery removed to stop a false alarm and never put back, a dead battery never replaced, a device past its 10-year lifespan, or an alarm painted over, dusty, or unhooked during renovations. In a multi-unit building, these lapses multiply by the number of dwellings — a triplex is three times as many opportunities for a device to be disabled without your knowledge.

This is exactly where the value of a 10-year sealed-battery alarm comes in: by removing the battery-replacement step, you eliminate the leading cause of failure. For a plex owner on the North Shore, standardizing this type of device across all units is not only a requirement in certain municipalities — it is a risk-management strategy that concretely reduces the odds of a unit ending up unprotected.

There is also a financial angle that owners rarely connect to these statistics. A fire that spreads because an alarm failed does not only threaten lives — it can wipe out years of rental income, trigger a lengthy rebuild, and complicate every future insurance renewal. Seen that way, the few dollars spent on compliant alarms and the few minutes spent logging them are among the highest-return "investments" you will ever make in a multi-unit building. The downside of skipping them is measured not in dollars, but in catastrophe.

Sources: Ministère de la Sécurité publique — Fire-safety statistics; Fire Safety in Québec — State of Play (April 2025).

How many alarms and where, exactly: a room-by-room guide

The "one alarm per floor" rule is a floor, not a ceiling. For a plex, the right question is not "do I have the minimum?" but "would every occupant be woken in time, wherever they sleep?". The Government of Québec spells out the expected locations, and they are more demanding than most owners assume.

The required locations in each dwelling

According to the official guidance, a smoke alarm must be installed on each floor, including the basement, in the hallway near the bedrooms, in each room where people sleep, and near the stairs. In a single-level unit as in a two-storey one, this grid has a single goal: that no sleeping person is separated from an alarm by a closed door and a smoke-filled hallway.

For large floors, the rule tightens: a floor longer than 10 metres should have two alarms, one at each end. In a multi-unit building with long shared corridors, this detail changes the total number of devices to plan for.

The exact position on the wall or ceiling

Placement within the room matters as much as the room itself. Smoke rises: a poorly placed alarm reacts too late. The official guidance states:

Also beware of locations that generate false alarms: too close to a kitchen or bathroom, an alarm will sound at every burnt toast or hot shower. Yet it is precisely the repeated false alarm that pushes a frustrated tenant to remove the battery — cancelling all protection. Thoughtful placement is therefore not a luxury: it is what keeps the device active.

Interconnecting electric alarms

If your plex is equipped with electric smoke alarms (hardwired at 120 V), they must be interconnected and activate simultaneously: when one device detects smoke, they all sound at once, regardless of where the fire starts. This is a major safety advantage in a multi-storey unit, where a basement fire must wake someone sleeping on the top floor. Electric models must also include a backup battery to keep working during a power outage.

Source: Government of Québec — Smoke alarms.

The maintenance schedule: monthly, yearly, every 10 years

Compliance is not a one-time event, it is a routine. An alarm installed on lease-signing day and never rechecked will, statistically, end up in the silent-alarm category. Here is the maintenance rhythm recommended by Québec authorities, translated into concrete steps for a plex owner.

Every month: the button test

The monthly test simply means pressing the alarm's button until it sounds. This checks the battery, the electronics, and the sounder. In a rented unit, it is generally the occupant who performs this test, since they are the only one present daily. Your role as landlord: remind them in writing at key handover and, ideally, in an instruction posted or handed out with the lease.

Every year: cleaning and verification

Once a year, the device should be cleaned (dust and cobwebs hamper detection) and its ability to detect smoke verified. This is also a good time to replace the battery of removable-battery models, even if it is not yet dead — a habit many tie to the fall clock change.

Every 10 years: full replacement

A smoke alarm must be replaced every 10 years from its manufacturing date, printed on the casing. Past that point, the sensor's reliability is no longer guaranteed, even if it seems to work. For a multi-unit owner, the best practice is to record each device's manufacturing date in a log and to plan replacements in waves, unit by unit.

The intermittent chirp (the annoying "beep" every few minutes) signals a low battery: replace it without delay, and above all do not simply pull the battery to stop the noise. That is the move that kills.

Source: Government of Québec — Smoke alarms.

Safety Code, the RBQ, and the 9-dwelling threshold

Many plex owners confuse two distinct regimes: standalone smoke alarms (a general obligation, framed by municipalities and provincial guidance) and fire alarm systems governed by the Building chapter of the Safety Code, administered by the Régie du bâtiment du Québec. Understanding where your building sits avoids nasty surprises.

Small plexes: the standalone-alarm regime

A low-rise duplex, triplex, or quadruplex falls first under the per-unit smoke alarm requirements and municipal fire-safety by-laws. This covers the vast majority of North Shore plexes. Here, the obligation boils down to providing, installing, and maintaining compliant alarms in the right locations — which is what most of this article covers.

The Building-chapter threshold: 3 storeys or 9 dwellings

The requirements of the Building chapter of the Safety Code notably target residential buildings of three storeys or more and comprising nine dwellings or more. Above this threshold, you are no longer dealing only with standalone alarms, but with a fire alarm system to maintain and have inspected periodically. A large income property therefore does not carry the same obligations as a triplex — worth keeping in mind if you own or covet a mid-size building.

When upgrading an existing fire alarm system, the most common required change is the addition of a sounder in each dwelling, so that every occupant hears the alarm from their own apartment. This work falls to a qualified contractor and must meet the standards in force.

Sources: Régie du bâtiment du Québec — Building chapter of the Safety Code; RBQ — Verification of fire alarm and detection systems.

Carbon monoxide in detail: combustion appliances, garages, symptoms

Carbon monoxide (CO) deserves a section of its own, because it is an invisible risk that too many plex owners underestimate. Unlike smoke, you cannot see it or smell it — and it kills several people every year in Québec, in poisonings that are most often accidental and preventable.

Each year in Québec, several hundred people fall victim to CO poisoning. In 2017 alone, the Québec Poison Control Centre received more than 750 consultations for suspected or confirmed exposures to carbon monoxide. These events often occur during the cold season, when heating appliances run at full tilt in closed dwellings.

Where CO comes from in a plex

Carbon monoxide is produced by the incomplete combustion of any fuel. In a multi-unit building, the typical sources are more numerous than people think:

The crucial point for a plex owner: the obligation is not limited to the unit that contains the appliance. It also covers any dwelling whose wall, floor, or ceiling is adjacent to a space housing a combustion appliance or a garage. A gas water heater in a shared laundry room, or a garage integrated beneath the units, can thus require CO alarms in several units at once.

This adjacency rule catches many owners off guard when they convert or renovate. Add a gas appliance to a basement common area, or enclose a carport into an attached garage, and you may create a CO-alarm obligation in units that had none before. Whenever you change a heating source, a fuel type, or the layout around a garage in your income property, re-run the checklist: which units are now adjacent, and do they each have a compliant CO alarm on the right floor?

Recognizing a poisoning

The symptoms of CO poisoning resemble those of the flu: headaches, nausea, fatigue, dizziness, confusion. That is precisely what makes them dangerous — they are blamed on something else. An alarm compliant with standard CAN/CSA-6.19, installed on each floor with a bedroom and near the bedrooms (never in a garage), is the only reliable way to detect the gas before it becomes deadly.

Sources: Government of Québec — Carbon monoxide alarms; INSPQ — Clinical toxicology (carbon monoxide poisoning).

The 10 most common plex-owner mistakes

After crossing paths with hundreds of multi-unit buildings during acquisitions on the North Shore, the same fire-safety blind spots keep coming up. Here they are, with the corrective reflex.

1. Relying on the tenant to install the devices. Installation and provision are the landlord's job, period. Never assume a unit is equipped without verifying it yourself.
2. Forgetting the basement and common areas. An alarm is required on each floor, basement included, and boiler or shared-laundry rooms are often overlooked.
3. Ignoring the CO alarm. Many owners install smoke alarms but forget carbon monoxide, mandatory since 2019 where there is a combustion appliance or adjacent garage.
4. Keeping expired devices. An alarm over 10 years old must be replaced, even if it "still works". The date is on the casing.
5. Placing the alarm too close to the kitchen. False alarms push tenants to remove the battery. Thoughtful placement preserves protection.
6. Painting over it. During renovations, an alarm painted or coated in plaster dust is neutralized. Protect it, then test it after the work.
7. Not interconnecting electric devices. Hardwired alarms must activate simultaneously; an isolated unit leaves part of the dwelling without warning.
8. Documenting nothing. Without a dated log, it is impossible to prove diligence to the insurer or before a court.
9. Neglecting the check between tenancies. Tenant turnover is the ideal — and often only — moment to inspect and replace everything as needed.
10. Assuming every municipality has the same rules. The 10-year sealed-battery requirements vary from one city to another; you must check the local by-law.

Plex, single-family home, or large building: what changes

The basic obligations are similar, but the scale of the task varies enormously by property type. Understanding where your plex sits helps calibrate the effort — and anticipate what awaits you if you change building class.

For a plex owner on the North Shore, the difficulty is not technical — an alarm costs little and installs in minutes — but organizational: you have to track several units, several tenants, several replacement dates, and document it all. This is exactly the kind of rigour a savvy buyer looks for at transaction time.

Because fire safety is not only a compliance question: it is an indicator of how well your income property is managed. A plex whose alarms are compliant, recent, and documented sends a clear signal — that of a careful owner, whose building has probably been well maintained otherwise. Conversely, missing or expired alarms found at a pre-purchase inspection feed doubt and, often, a lower offer.

Between tenancies: the critical verification window

Tenant turnover is, for a plex owner, the most valuable — and most often wasted — moment to bring fire safety up to standard. The unit is empty, accessible, and you need no one's permission to enter. It is the ideal window to check everything and restart on a documented footing.

The end-of-lease checklist

Before handing the keys to the next occupant, go over each unit with a fine-tooth comb:

• Test each smoke and CO alarm with the button;
• Check the manufacturing date on the casing and replace any device over 10 years old;
• Replace the battery of removable models, or the whole device if the sealed battery is nearing its end;
• Confirm the locations: each floor, near bedrooms, in bedrooms, near stairs, basement included;
• Make sure no device was painted, unhooked, or obstructed by the previous tenant;
• Record the date, models, and actions taken in your log.

The right of access during the lease

During the lease, you cannot enter an occupied unit at will to check the alarms: the tenant is entitled to peaceful enjoyment of the premises, and prior notice is required for most visits. Systematic verification between tenancies is precisely what avoids having to multiply visits to an occupied unit. When a check is unavoidable during the lease — for instance after a report — respect the notice rules and favour cooperation with the occupant.

This discipline turns a regulatory constraint into a patrimonial asset: when it comes time to sell your multi-unit building, a spotless fire-safety file reassures the buyer and removes a downward-negotiation card from their hand.

Beyond the obligation: evacuation plan and safety culture

An alarm that sounds is useless if no one knows what to do next. Without turning your plex into a fire hall, a few simple steps strengthen your occupants' real safety — and your position in a dispute, by demonstrating diligence that exceeds the bare minimum.

Give each new tenant, in writing, the location of the alarms, how to test them, and the number to call in an emergency. Encourage each household to plan two exit routes and an outdoor gathering point — a particularly important reflex in Québec plexes with exterior staircases, where the secondary access may be a rear balcony.

For the carbon monoxide alarm, the instruction differs from fire: when it sounds, get outside into fresh air immediately and call for help, without trying to ventilate the space yourself. Reminding occupants of this distinction can literally save a life, because the instinctive reflex — opening a window and staying put — is the wrong one.

This safety culture costs almost nothing and sets apart the genuinely responsible owner. It follows the same logic as documentation: beyond the letter of the by-law, it shows you took your obligations seriously — a valuable argument before an insurer, a court, or a buyer.

Insurance: the clauses to check in your policy

We keep saying that non-compliant alarms can cost you a payout; it helps to understand why. Most income-property insurance contracts include obligations of the insured regarding safety equipment: the insurer expects the owner to maintain compliant, functional alarms. A breach can serve as grounds to reduce, or even refuse, a payout after a claim. This is not a theoretical threat — it is written into the policy conditions.

What to re-read in your contract

• The obligations related to protective devices: presence, upkeep, and compliance of smoke and CO alarms;
• The heating-related requirements: a wood stove or oil furnace may impose specific conditions (WETT certificate, annual servicing);
• Accurate declarations: number of units, presence of a garage, type of heating — an inaccuracy can void coverage;
• The deductibles and exclusions that apply in the event of a fire.

For a plex owner on the North Shore, the winning reflex is to treat alarm compliance and the insurance file as a single whole. A dated log — installation dates, models, ULC and CAN/CSA-6.19 standards, checks between tenancies — is not only legal protection: it is also the proof the insurer will ask for to establish your diligence, and the one a buyer will demand when you sell your multi-unit building.

If you are unsure how to interpret a clause or how responsibility is split, speak with your property-and-casualty insurance broker and, for legal matters, a lawyer or notary. It is better to clarify before a loss than after.

One last habit pays off handsomely: keep photographs. A dated photo of each installed alarm, showing the manufacturing date on the casing and the mounting location, turns your written log into hard evidence. Stored alongside your lease files and maintenance records, this small archive is exactly what an adjuster, a court, or a buyer's inspector wants to see — proof that the protection existed and was in order, not merely a claim that it was.

In short, smoke and CO alarms are an area where compliance is simple, inexpensive, and heavy with consequences if neglected. Check your municipality's by-law, install compliant devices, replace them on time, and document everything. Your income property — and your peace of mind — will be better for it.

Informational content only. Fire-safety rules and effective dates are subject to change by the Régie du bâtiment du Québec, the Québec government, and municipalities. Consult a professional for advice specific to your building and municipality.