Smoke and carbon monoxide alarm requirements for rental units
Fire safety agencies recommend smoke alarms inside and outside each sleeping area and on every level, tested monthly and replaced every 10 years, and carbon monoxide alarms outside each sleeping area and on every level wherever fuel-burning appliances are present. State law then decides what a landlord must install and maintain. Texas requires a smoke alarm in every bedroom and a working test at each move-in; New York requires carbon monoxide detectors in multiple dwellings with fuel-burning appliances or an attached garage.
What fire safety agencies recommend
The U.S. Fire Administration, part of FEMA, gives the baseline most codes build on (USFA, Smoke alarms):
- Put smoke alarms inside and outside each bedroom and sleeping area, and on every level of the home.
- Choose interconnected alarms so that when one sounds, they all sound.
- Test alarms monthly.
- Replace batteries at least once a year in alarms that use replaceable batteries, including the backup battery in hardwired alarms.
- Replace the entire alarm 10 years from its manufacture date.
For carbon monoxide, the USFA advises installing alarms in a central location outside each separate sleeping area and on every level (USFA, Carbon monoxide). The CDC adds that CO detectors should be replaced according to the manufacturer's instructions or every 5 years (CDC).
Texas: one in every bedroom
Texas Property Code Subchapter F sets the landlord's smoke alarm duties (Texas Property Code 92.251 to 92.264):
- At least one smoke alarm in each separate bedroom; one in the corridor next to the bedrooms when several bedrooms share a corridor; one on each level of a multi-level unit; and one inside the room for a studio where one room is used for living and sleeping (92.255).
- Units occupied or given a certificate of occupancy before September 1, 2011 may use battery alarms that are not interconnected (92.255(b)).
- Mount on the ceiling at least six inches from a wall, or on a wall between six and twelve inches from the ceiling, unless the manufacturer's instructions say otherwise (92.257).
- Test each alarm at the start of each tenant's possession; during the lease, inspect and repair after the tenant reports a problem (92.258).
- The landlord need not supply replacement batteries after move-in if the alarm worked at the start (92.258(f)).
- A tenant who removes a battery without replacing it or disables an alarm can be liable, if the lease carries the required notice (92.2611).
The subchapter does not apply to units in buildings of five or more stories where a local ordinance regulates smoke alarms (92.253), and it does not address carbon monoxide alarms, so check your city's code.
Florida and New York
Florida's landlord-tenant statute requires working smoke detection devices at the start of a tenancy of a single-family home or duplex, unless otherwise agreed in writing (Florida Statutes 83.51(2)(b)). For apartment buildings, alarm requirements come mainly from the building and fire codes that Section 83.51(1) requires landlords to follow.
New York's Executive Law 378 requires an operable carbon monoxide detector in one- and two-family homes, condominiums and multiple dwellings (generally buildings housing three or more families), where the unit has appliances, devices or systems that may emit carbon monoxide or has an attached garage. It also requires smoke alarms that are clearly audible in each bedroom or room used for sleeping, and notification audible in common spaces of buildings with three or more units (NY Executive Law 378). New York City and other localities add their own rules.
Many other states have their own smoke and carbon monoxide statutes, and local fire codes often go further. Check your state and city codes, and ask your local fire marshal if you are unsure.
Count what a building needs
Example a made-up 12 unit Texas building, one story per unit, each unit with two bedrooms off one hallway and a gas furnace. Smoke alarms: 2 bedrooms + 1 hallway = 3 per unit, so 12 x 3 = 36. Carbon monoxide alarms, following USFA guidance of one outside the sleeping area per level: 1 per unit, so 12. Total: 48 alarms. At a 10-year life for smoke alarms, about 3 or 4 smoke alarms a year reach replacement age once the building settles into a rolling schedule (36 / 10 = 3.6).
Keep a testing log
A log is your proof that alarms worked when a tenant moved in and that you responded when one failed.
| Field | Why |
|---|---|
| Unit and location (bedroom 1, hallway) | Shows each required spot is covered |
| Type (smoke, CO, combination) and power (battery, hardwired) | Tells you what to stock |
| Manufacture date | Sets the replacement date |
| Date tested and by whom | Proves the move-in test |
| Result and action taken | Shows repairs after a report |
Test at every turn as part of the make-ready checklist, and test common-area alarms monthly.
Alarms and DoorKeeping
DoorKeeping records what you spend on alarms and batteries in each property's books, as supplies or repairs on the matching Schedule E line, and any purchase payment waits for your approval. The testing itself is yours or your vendor's; DoorKeeping gives no legal advice on which code applies to your building.
Sources
- U.S. Fire Administration, Smoke alarms, read Oct 29, 2026
- U.S. Fire Administration, Carbon monoxide, read Oct 29, 2026
- CDC, About Carbon Monoxide Poisoning, read Oct 29, 2026
- Texas Property Code, Chapter 92, Subchapter F, read Oct 29, 2026
- Florida Statutes 83.51, read Oct 29, 2026
- New York Executive Law 378, read Oct 29, 2026
Questions
- Are landlords required to replace smoke alarm batteries?
- It depends on the state. In Texas, a landlord need not supply batteries after move-in if the alarm worked when the tenant took possession. Other states and cities differ.
- Where should carbon monoxide alarms go in an apartment?
- The U.S. Fire Administration recommends a central location outside each separate sleeping area and one on every level. Follow your state code and the alarm maker's instructions too.
- How often should smoke alarms be replaced?
- The U.S. Fire Administration says to replace the whole alarm 10 years from its manufacture date, and to test it monthly.