Electricity and water have never been compatible, and the design of an electrical installation in wet rooms, such as a bathroom, requires particular caution because they are more exposed to risks than other rooms in the home. The NF C 15 - 100 standard provides recommendations on this subject.

Protection Volumes: a Concern for Safety

For the bathroom, the NF C 15 - 100 standard distinguishes different types of volume, each corresponding to a level of exposure:

• Volume 0: this is the area where water is received (bath or shower). No electrical equipment is allowed in this area.
• Volume 1: it is constituted by the zone in which the water is projected around volume 0, delimited by the edges of the shower tray and/ or by a height of 2,25 meter.
• Volume 2: it corresponds to a safety zone around the shower tray, on a distance of 60 centimeter beyond volume 1.

The hidden volume: it is the space under the bathtub or the shower tray. No electrical equipment is allowed here (except for Ingress Protection 4 products protected by a 30 milliampere differential switch, such as a whirlpool motor).

The rest of the bathroom is considered "Out of Volume".

Note: only fixed and permanent walls joined to the floor limit the volumes.

Volumes 0, 1 and 2

Volume 0: case of walk in showers (without shower tray)

Hidden volume

Which Equipment in Which Volume(s)?

The volumes defined by the NF C 15 - 100 standard determine the installation of electrical circuits and devices according to their protection measure.

Please note: the NF C 15 - 100 standard requires that all electrical circuits supplying a bathroom be protected by a 30 milliampere differential switch. In order for this switch to play its protective role, the pipes, metal masses and lighting in the bathroom must be connected to the ground.