"How many alarms do I need, and where exactly do they go?"
If you let property in England, the rules are shorter than most landlords expect. The wiring and the brand rarely cause trouble. The detail that catches people out is the day the tenancy starts. You can place every alarm correctly and still be in breach if you skip one small step on move-in day.
Here is what the law asks of you, room by room, and the one habit that keeps you on the right side of it.
The rule in one paragraph
The Smoke and Carbon Monoxide Alarm (England) Regulations 2015, as amended by the 2022 Regulations that came into force on 1 October 2022, require a private landlord to fit:
- at least one smoke alarm on every storey used as living accommodation, and
- a carbon monoxide (CO) alarm in any room used as living accommodation that contains a fixed combustion appliance, other than a gas cooker.
You must also make sure every alarm is working on the first day of a new tenancy. Sources: The Smoke and Carbon Monoxide Alarm (England) Regulations 2015, the 2022 amendment, and the government's guidance for landlords on GOV.UK.
Where the alarms go, room by room
The regulations do not fix exact positions. They expect you to follow the manufacturer's instructions. In practice that means smoke alarms on the ceiling in a circulation space, and CO alarms at head height, roughly 1 to 3 metres from the appliance.
| Location | Smoke alarm | CO alarm | Notes |
|---|---|---|---|
| Hallway or landing (each storey) | Yes, one per storey | Only if an appliance is present | Ceiling-mounted in the circulation space |
| Living room with a wood burner or open fire | Recommended | Yes | Solid fuel always needs a CO alarm |
| Kitchen or utility with a gas or oil boiler | Recommended | Yes | Gas cooker is excluded; a boiler is not |
| Bedroom with a gas fire | Recommended | Yes | Any fixed combustion appliance triggers it |
| Bathroom or WC | Counts toward the storey rule | Usually no | Still a "storey" for the smoke-alarm count |
| Garage-only floor | No | No | A storey used solely as a garage is excluded |
One point on storeys: a floor counts if it has any room used wholly or partly as living accommodation, and that includes bathrooms and toilets. So a loft conversion with only a shower room still needs its own smoke alarm.
The day-one test that catches landlords out
Under Regulation 4, on the day a new tenancy begins you or your agent must check that each alarm is in proper working order. That means pressing the test button, not assuming it still works from the last inspection.
A renewal with the same tenant does not re-trigger the first-day test, but testing at every change and periodically in between is sensible. Either way, record it: the date, who tested, and the result. A signed line in your check-in report or inventory is the evidence that protects you if a dispute arises later.
What changed in 2022
Before 1 October 2022, a CO alarm was only required where there was a solid fuel appliance, such as a log burner or coal fire. The amendment widened this to any fixed combustion appliance except a gas cooker. Gas boilers, gas fires and oil boilers now all need a CO alarm in the room. The 2022 changes also extended the duties to the social rented sector and confirmed that a landlord must repair or replace a faulty alarm once a tenant reports it.
Worked example: a two-storey terrace
The figures below are illustrative. Your own prices will vary, so treat this as a template for your own maths rather than a quote.
Take a two-storey, three-bed terrace with a gas combi boiler in the kitchen and a wood-burning stove in the living room, and no other combustion appliances.
What the rules require:
- Smoke: one on the ground floor, one on the first-floor landing = 2 smoke alarms.
- CO: one in the living room (wood burner), one in the kitchen (gas boiler) = 2 CO alarms. The gas hob is excluded.
Illustrative fit-out cost:
| Item | Qty | Unit (illustrative) | Total |
|---|---|---|---|
| Smoke alarms | 2 | £20 | £40 |
| CO alarms | 2 | £25 | £50 |
| Total | £90 |
Now set that against the downside. A local housing authority can serve a remedial notice, and if you fail to act it can impose a penalty charge of up to £5,000 (GOV.UK). A roughly £90 fit-out against a £5,000 penalty is not a close call.
If a tenant reports a faulty alarm
Once a tenant tells you an alarm has stopped working, you must repair or replace it as soon as reasonably practicable. Give tenants an easy way to report faults, and log both the date you were told and the date you fixed it. That paper trail is what shows you met the duty.
Scotland and Wales are different
This article covers England. The rules differ across the UK:
- Scotland: since February 2022, every home (including owner-occupied) must have interlinked alarms to a set tolerance-based standard.
- Wales: under the Renting Homes (Wales) Act 2016, rented homes need interlinked, mains-wired alarms as part of the fitness standard.
Check the current requirements for the nation your property sits in before a new let.
A five-minute checklist
- One smoke alarm on each living storey, tested and working.
- A CO alarm in every room with a fixed combustion appliance, excluding the gas cooker.
- Test every alarm on day one of a new tenancy, and log it.
- Follow the manufacturer's placement instructions.
- Fix any reported fault as soon as reasonably practicable.
This is general information, not tax or financial advice. Alarm rules differ across the UK and change over time, so check the current GOV.UK guidance for the nation your property is in before your next tenancy begins.
