Where to place a smoke detector: rules and locations

In short: a smoke detector is best placed on the ceiling of the hallway or landing that serves the bedrooms, high up and away from sources of steam. In France, at least one detector has been mandatory in every home since 8 March 2015, and one per floor is recommended. Kitchens and bathrooms are not advisable, and shared areas of apartment buildings are prohibited.

Knowing where to place a smoke detector determines how useful it is: badly positioned, it sounds too late or goes off every time someone cooks. Its job is simple, to detect smoke as soon as a fire starts and give a signal loud enough to wake a sleeping person. French regulations set a reference location, which practical advice completes room by room. This guide covers the legal requirements in France, the right locations, those to steer clear of, mounting and maintenance.

Where to place a smoke detector: locations at a glance

The table below sums up the recommendations, from the priority location to the prohibited ones.

What French law says about smoke detectors

Since 8 March 2015, every dwelling in France, apartments and houses alike, must be fitted with a standard-compliant smoke detector. The obligation comes from the law of 9 March 2010, specified by a decree of 10 January 2011 and an order of 5 February 2013. The rules in force now sit in the French Construction and Housing Code, and the official Service-Public page summarises them.

At least one detector in every home

Each home must have at least one smoke detector. The device must carry the CE marking and a reference to the NF EN 14604 standard. It runs on batteries, or on mains power provided it has a backup supply. Ionisation detectors are banned because they are radioactive.

The location set by the regulations

The regulations require the detector to be installed preferably in the circulation area serving the bedrooms, that is the hallway or landing. It must be firmly fixed in the upper part, close to the highest point, and away from other walls and from sources of steam. In a studio with no hallway, it goes as far as possible from the kitchen and the bathroom. Installing a detector in the shared areas of an apartment building is prohibited: the alarm would prompt residents to leave their homes and walk into the smoke.

Who installs and who maintains?

As a rule, the owner installs the detector and the occupant maintains it and replaces it if needed. In a rental, the owner also checks that it works at the move-in inventory. In a furnished rental, a seasonal rental, tied accommodation, a residential hostel or a social hotel residence, the owner takes on all of the obligations.

The certificate for the insurer

The occupant informs their home insurer of the installation by handing over a certificate, together with proof of purchase or installation. The regulations provide no penalty for the absence of a detector. After a fire, the insurer cannot refuse compensation on that ground alone, but it can reduce the payout if it proves that the missing detector made the consequences worse.

Where to install a smoke detector depending on the home

The reference location set by law then adapts to the layout of each house or apartment.

In a single-level apartment

The hallway leading to the bedrooms is the ideal spot: the detector picks up smoke before it reaches the rooms where people sleep, and the siren can still be heard with the doors closed. When all the bedrooms open onto the same hallway, a detector in the middle of that hallway serves them. When they are far apart, at both ends of the home for example, a second device is preferable.

In a house with several floors

Service-Public recommends one detector per floor in houses and apartments on several levels. The landing on the bedroom floor remains the priority, then the ground floor, on the ceiling of the entrance hall or living room. A large home justifies several detectors, even on a single level.

In a studio

Without a hallway, the detector goes on the ceiling, as far as possible from the kitchenette and the shower room. The centre of the main room, away from the cooker hood and the bathroom door, is often suitable.

In the living room and bedrooms

These rooms are not required, but they can take an additional detector. The living room often concentrates electrical appliances, chargers and sometimes a fireplace or stove. The detector belongs in the centre of the ceiling there, away from heat sources.

Ceiling or wall: how to mount the detector

Hot smoke rises and builds up under the ceiling first. That is why the regulations require mounting in the upper part, near the highest point. The centre of the ceiling is the safest location; corners, where air circulates poorly, should be ruled out. Wall mounting should only be considered if the manufacturer’s instructions allow it, following the distances they give from the ceiling and corners.

Mounting requires little work: a base screwed to the ceiling, sometimes an adhesive or magnetic fixing depending on the model. Once the device is in place, pressing the test button confirms that the alarm works and can be heard from the bedrooms.

Locations to steer clear of

Some spots cause needless alarms or delay detection. Prevention guides agree on several of them:

• Kitchen and bathroom: cooking fumes and steam trigger false alarms. It is better to place the detector just outside, in the hallway.
• Near a heating appliance: stove, fireplace, radiator or boiler. Several insurer guides advise keeping a gap of about 3 metres.
• In a draught: near a window that is often open, a ventilation outlet or a fan, the airflow pushes smoke away from the sensor.
• The garage: exhaust fumes disrupt a smoke detector. A carbon monoxide detector is more suitable there if a boiler is installed.
• Uninsulated lofts and attics: extreme heat and cold, dust and insects impair the device.

Choosing a compliant, suitable detector

The CE marking together with the NF EN 14604 reference is mandatory in France. Beyond this baseline, several options meet specific needs. Detectors with a light or vibrating signal exist for deaf or hard-of-hearing people. In a house with several floors, interconnected models make every detector sound as soon as one of them reacts. A connected detector sends the alert to the smartphone, on the same principle as a security camera viewed remotely.

Connected detectors also send a notification to the smartphone, which is useful when the home is empty. Linked to a home automation hub, they can trigger other actions, such as switching on the hallway lights. The principle of these routines is explained in the guide to the home automation definition. A connected detector is subject to the same placement rules as a standard model.

Maintaining and testing a smoke detector

A well-placed detector is only useful if it works. Maintenance falls to the occupant and comes down to a few steps:

• press the test button regularly, for example once a month as many prevention guides recommend;
• dust the device, since dust can hinder detection;
• replace the batteries as soon as the low-battery signal sounds, if they are not sealed;
• replace the detector on the date given by the manufacturer, often around ten years.