Short answer: in England a new or replacement fixed solid fuel appliance in a dwelling needs a carbon monoxide alarm in the same room. The alarm goes either on the ceiling at least 300 mm from any wall, or on a wall as high as possible above doors and windows but not within 150 mm of the ceiling, and in both cases between 1 m and 3 m horizontally from the appliance. It should meet BS EN 50291-1:2018, and if it is mains powered it has to be fixed-wired, not plugged in.
Those three paragraphs of Approved Document J, 2.34 to 2.36, are short and precise, and they get misread in two directions: alarms fitted next to the stove where they alarm on every refuel, and alarms fitted by the door on the far side of the room where they are outside the range the document names.
The requirement
Paragraph 2.34: where a new or replacement fixed solid fuel appliance is installed in a dwelling, a carbon monoxide alarm should be provided in the same room as the appliance.
Three words carry the weight. Fixed: a permanently installed stove, not a portable heater. Solid fuel: wood, coal, smokeless fuel, pellets. Same room: not the hallway, not the landing, not “somewhere central”. The alarm is there to catch the appliance in front of it.
The alarm itself
Paragraph 2.35 describes what counts as a suitable alarm. It should comply with BS EN 50291-1:2018, and be powered in one of two ways:
- Battery powered, by a battery designed to operate for the working life of the alarm, with a warning when the battery is running down; or
- Mains powered, as a Type A alarm with fixed wiring, not plug-in, and a sensor failure warning.
The “fixed wiring” phrase is the one people trip over. A mains alarm on a plug does not meet the description, for the obvious reason that a plug can be pulled out to free the socket. In practice most stove installations use a sealed long-life battery alarm, which needs no wiring and satisfies the first option.
Where it goes
Paragraph 2.36 gives two mounting positions and one distance rule.
| Mounting | Rule |
|---|---|
| On the ceiling | At least 300 mm from any wall |
| On a wall | As high as possible, above any doors and windows, but not within 150 mm of the ceiling |
| Either | Between 1 m and 3 m horizontally from the appliance |
The reasoning is simple once you picture the gas. Carbon monoxide leaving a faulty appliance is warm and rises, then spreads across the ceiling. An alarm right in the corner, where wall meets ceiling, sits in a pocket of dead air that the spreading gas reaches last; the 300 mm and 150 mm rules keep it out of that pocket. The distance band keeps the alarm close enough to respond to the appliance in front of it, but not so close that the normal puff of smoke on opening the door sets it off, which is how alarms end up with their batteries removed.
A worked position
A 4.2 m long living room with the stove on the short wall. The stove is 0.5 m deep, so its front face is 0.5 m into the room. Measuring horizontally from the appliance:
- 1 m to 3 m from it places the alarm somewhere between 1.5 m and 3.5 m along the room from the stove wall.
- Ceiling mount in that zone, at least 300 mm from the side walls, is the straightforward choice.
- Wall mount is only available if a wall falls inside the zone. The far wall is 4.2 m away, outside it; a side wall is inside it. On a side wall the alarm goes as high as possible above the door and window heads, but at least 150 mm below the ceiling.
Stove Toolkit checks a proposed position against all three rules and tells you which one a placement fails, so you can fix the position rather than guess.
Manufacturer’s instructions
Alarm manufacturers publish their own siting guidance, and it should be read alongside these paragraphs. Where the manufacturer is more restrictive, follow the manufacturer. Where it appears to allow something Approved Document J does not, the AD J position is what building control or a competent installer will expect to see.
An alarm is not a safety strategy
Paragraph 2.36 ends with a line that is easy to skip: an alarm is no substitute for correct installation and regular servicing. The alarm catches the failure after the fact. The things that prevent the failure are the right flue, the right ventilation, and a chimney that is swept. Our guides on log burner air vents and flue size cover the first two.
Rented homes are a separate question
England also has regulations specifically for smoke and carbon monoxide alarms in rented homes, which impose their own duties on landlords independently of the building regulations. They are a different legal basis and are not covered here. Landlords should read the government’s explanatory booklet rather than rely on the AD J position alone.
Scope
England, Approved Document J, 2010 edition incorporating the 2010, 2013 and 2022 amendments, paragraphs 2.34 to 2.36. Wales publishes its own version; Scotland and Northern Ireland have different requirements. Installing a solid fuel appliance is building work that must be carried out by a competent person, such as a HETAS registered installer, or notified to building control before it starts. Read the source at Approved Document J on gov.uk.
Figures checked against the gov.uk PDF of Approved Document J on 11 September 2026. Contains public sector information licensed under the Open Government Licence v3.0. Plan CD is not affiliated with HETAS, DEFRA or any manufacturer; HETAS is a trade mark of its owner.