The short version
- Nearly every state requires smoke alarms in rentals, and many require carbon monoxide alarms where there is a fuel burning appliance or attached garage.
- Common guidance puts smoke alarms in every bedroom, outside each sleeping area and on every level, and CO alarms outside sleeping areas and on every level.
- Smoke alarms should be replaced 10 years after the date of manufacture. CO alarms often have a shorter life; follow the date on the unit.
- Test and document every alarm at each move-in and during routine inspections. Have tenants sign that alarms worked.
- Most states put installation on the landlord and day to day testing and battery changes on the tenant. Check yours.
Smoke and carbon monoxide alarms are cheap, and they are among the most important safety devices in a rental. They are also an area where small lapses carry large consequences. A missing alarm or an expired unit can expose you to liability after a fire, and in many states it is a code violation regardless of whether anything happens.
This guide covers where alarms go, which types to use, how long they last, who tests them, and how to keep records that show you did your part.
What the law usually requires
Smoke alarm requirements exist in virtually every state, usually through the state fire code, building code or a landlord tenant statute. Carbon monoxide requirements are now common as well, typically triggered when a home has a fuel burning appliance (a gas furnace, water heater, stove or dryer), a fireplace or an attached garage.
The details vary in ways that matter:
- Which type of power is required: hardwired with battery backup, sealed 10 year battery, or replaceable battery
- Whether alarms must be interconnected, so one sounding triggers them all
- Whether combination smoke and CO units are allowed
- Who must test and when, including at each new tenancy
- Who replaces batteries, landlord or tenant
- Written disclosures or a signed statement at move-in
Many local building codes adopt model codes and require hardwired, interconnected alarms in new construction and major renovations. Check your state law and your local fire marshal or code office.
Where to put them
Common guidance from fire safety organizations and model codes suggests:
Smoke alarms
- Inside every sleeping room
- Outside each sleeping area, in the hallway near the bedrooms
- On every level, including basements
- Away from kitchens and bathrooms by a few feet, to cut down on nuisance alarms from cooking and steam
Carbon monoxide alarms
- Outside each sleeping area
- On every level
- Near, but not right next to, fuel burning appliances, following the manufacturer’s spacing
Mount according to the instructions, usually on the ceiling or high on a wall, and away from windows, doors and vents where drafts can interfere.
Worked example: a two story house
A three bedroom house with a gas furnace and water heater in the basement, bedrooms upstairs, and an attached garage:
| Location | Smoke | CO |
|---|---|---|
| Bedroom 1 | Yes | |
| Bedroom 2 | Yes | |
| Bedroom 3 | Yes | |
| Upstairs hallway outside bedrooms | Yes | Yes |
| Main floor (living area, not in the kitchen) | Yes | Yes |
| Basement | Yes | Yes |
| Total devices | 6 | 3 |
Combination units in the hallway, main floor and basement would cover both needs with six devices instead of nine, if your local rules allow combination units. If local code requires interconnection, a renovation is a good time to add it.
Types of alarms
- Ionization smoke alarms respond somewhat faster to fast flaming fires.
- Photoelectric smoke alarms respond somewhat faster to slow smoldering fires and tend to cause fewer nuisance alarms from cooking.
- Dual sensor alarms combine both.
- Combination smoke and CO alarms cover both hazards in one device.
- Alarms for people who are deaf or hard of hearing use strobe lights or bed shakers. If a tenant asks for one, treat it as a reasonable accommodation request. Our fair housing basics post covers the process.
Many fire safety groups recommend photoelectric or dual sensor alarms. Whatever you choose, use one model across your portfolio so tenants and staff know how it works and you can stock spares.
How long alarms last
- Smoke alarms: replace 10 years after the date of manufacture printed on the back, or sooner if they fail a test.
- CO alarms: lifespan varies by model, often 5 to 10 years. Many sound an end of life chirp. Follow the date on the unit.
Record the manufacture date for each alarm in your unit records. An alarm installed new in a unit last year may have been made several years earlier.
Who does what
A clear split avoids confusion. A common arrangement:
| Landlord | Tenant |
|---|---|
| Install working alarms that meet code | Test alarms monthly |
| Test every alarm at move-in and document it | Replace batteries (unless sealed units) |
| Replace failed or expired units | Report any alarm that does not work |
| Respond quickly to reports of problems | Never disable or remove an alarm |
| Check alarms during routine inspections | Allow access for testing and replacement |
Put this in the lease or a short addendum, and have tenants initial it. Some states have a required form. Our lease addendum guide explains how to attach one.
Testing at turnover and move-in
The moment the unit changes hands is when you have the clearest responsibility and the easiest access.
- During the make-ready, test every alarm, check manufacture dates, replace batteries in replaceable battery units, and replace any unit near its end of life. Our make-ready turnover guide includes this step.
- At the move-in walkthrough, press the test button on each alarm with the tenant watching.
- Record it on the move-in checklist: location, type, manufacture date and test result. Have the tenant sign.
- Show the tenant how to test and silence the alarm, and what the low battery and end of life chirps sound like.
In TenantLoop, a move-in inspection walks you item by item with photos, so you can add each alarm as an item, photograph the label with its date, and mark it Good. The PDF report carries the photos and your notes. See inspections and our move-in process guide.
During the tenancy
- Send a reminder twice a year asking tenants to test alarms. Many landlords tie it to the clock change.
- Check alarms during routine inspections, with notice. Our inspection photo guide covers routine visits.
- Treat a report of a non working alarm as urgent. A missing or dead alarm is a safety issue. Our post on emergency versus routine maintenance explains how to set priority levels.
- Make alarm replacement a recurring work order keyed to each unit’s manufacture dates. In TenantLoop, recurring work orders repeat on the schedule you set, each with its own due date and assignee. See work orders.
When a tenant disables an alarm
It happens, usually because of cooking smoke or a chirping battery. If you find a disabled alarm:
- Restore it immediately, or replace it.
- Photograph the condition you found.
- Send the tenant a written reminder of the lease terms and the safety risk.
- Consider whether the alarm’s location causes nuisance alarms, and move it or switch to a photoelectric model if so.
Repeated tampering may be a lease violation, and many states treat disabling an alarm as an offense.
Records
For each unit, keep:
- Alarm locations, types and manufacture dates
- Move-in test results signed by the tenant
- Dates of battery changes and replacements
- Tenant reports and your response times
- Reminders sent
These records are what show you met your obligations if there is ever a fire or CO incident.
Common mistakes
- Missing alarms in bedrooms
- No CO alarm in a home with gas appliances or an attached garage
- Expired smoke alarms still on the ceiling
- No record of the move-in test
- Treating a dead alarm report as routine
- Different alarm models in every unit, with no spares
Smoke and CO alarm requirements come from state law, local building and fire codes, and sometimes city ordinances. This post is general information. Check your state and local requirements and follow each manufacturer’s instructions.
If you are doing this for real.
Who is responsible for changing smoke alarm batteries in a rental?
In many states the tenant is responsible for testing alarms and replacing batteries during the tenancy, while the landlord is responsible for installing working alarms and replacing units that fail. Some states require sealed 10 year battery alarms, which removes the battery question. Put the split in your lease.
Do I need carbon monoxide alarms in an all electric building?
Many state laws only require CO alarms where there is a fuel burning appliance, a fireplace or an attached garage. An all electric building without an attached garage may be exempt, but local codes vary. Installing them anyway is inexpensive.
Should I use hardwired or battery alarms?
Local building codes often require hardwired, interconnected alarms in new construction and major renovations. For existing buildings, battery alarms are often allowed, and some states require sealed long life batteries when replacing battery only alarms. Follow your local code.
What should I do if a tenant disables an alarm?
Restore it immediately, document the condition with photos, and remind the tenant in writing of the lease terms and the safety risk. Many states make tampering with a smoke alarm a violation. Repeated tampering may be a lease violation you can act on.