A bathroom is a damp interior, a place where electricity encounters moisture. So when luminaires are installed, certain rules need to be observed to ensure safety. These are set out in DIN VDE 0100, Part 701. The standard distinguishes between four different room zones, three of which have special safety requirements.

Safety zone 0

Zone 0 relates to the inside of the bathtub or shower tray. Only luminaires operating on a protective extra-low voltage of 12 V or less may be used here; they must also be specifically approved for use in a bathtub or show tray and need to be protected to IP X7.

Safety zone 1

Safety zone 1 is bounded by the vertical surfaces or planes at the outer edge of the bathtub or shower tray. Where no shower tray is present, the zone extends to a radius of 120 centimetres around the shower head at rest. The upper limit of the zone is 2.25 metres above floor level, the lower limit is the floor.

Safety zone 1 also requires the use of protective extra-low voltage luminaires operating on a maximum voltage of 12 V. They require a protection rating of at least IP X4, affording protection against spraywater.

There must be no transformers mounted in either safety zone 0 or 1.

Safety zone 2

Safety zone 2 is a 60 centimetre deep strip adjoining safety zone 1. Luminaires in this zone require a protection rating of at least IP X4, affording protection against spraywater. Where massage jets etc. are installed, luminaires are required to be protected to IP X5 – against jets of water.

Outside these defined safety zones, luminaires do not require a heightened degree of protection.

Electrical sockets

No switches or sockets may be installed in safety zones 0, 1 and 2. An exception is made in the case of switches integrated in luminaires – provided they do not lower the degree of protection of the luminaire.

Incidentally, light plastic-sheathed cables to luminaires may be laid on or under plaster in bathrooms; flat-webbed cables may be laid only under plaster at a minimum depth of six centimetres.