Cost guide
How much do smoke alarms cost?
Three interlinked mains alarms fitted is £300 to £600, and a radio interlinked sealed battery set of the same size £180 to £400. A larger house needing five or six devices runs to £500 to £900.
Typical prices
Ranges, not quotes. A quote depends on your room.
| Work | Typical UK price |
|---|---|
| Three mains alarms, cabled interlink | £300 to £600 |
| Three sealed alarms, radio interlink | £180 to £400 |
| Five or six devices, larger house | £500 to £900 |
| Carbon monoxide detector added | £45 to £90 |
| Replacing alarms at end of life, existing wiring | £120 to £280 |
| Dedicated alarm circuit from the board | £120 to £260 |
Alarms have a replacement date printed on the back, usually ten years from manufacture, and a house fitted out in one go reaches it in one go. Write the year on the ceiling rose in pencil and the next owner will thank somebody.
What moves the price
- Number of storeys and circulation spaces, which sets the device count before anything else.
- Hard wired with a cabled interlink against sealed cells with a radio interlink.
- Whether there is loft and floor access for cabling, or whether ceilings would have to be cut.
- Whether a dedicated circuit is run or the alarms are fed from an existing lighting circuit.
- Carbon monoxide detection where there is a boiler, a fire or a flue.
- Making good after cabling, in a house with plastered ceilings and no access.
Who quotes for it
Questions about smoke alarms
Why a heat alarm in the kitchen and not a smoke alarm?
Because a smoke alarm near a cooker triggers on toast, and an alarm that triggers on toast gets its battery taken out. A heat alarm responds to temperature rise instead and stays in place.
Does the system need testing or certifying?
Hard wired alarms are on a circuit, so the installation is certified like any other electrical work. Beyond that it is a weekly test button and a look at the manufacturer's replacement date, which is usually ten years from fitting.