Bathroom Zones Explained

By Ben Victor

Updated: 9th August 2023

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Bathroom Zones are special areas or “zones” in your bathroom which indicate the level of potential danger posed to you by electrical appliances and electricity itself. As you may know, water and electricity can make quite a lethal combo. Alongside the specific instructions published in the Wiring Regulations, bathroom zones are designed to keep you and installers or contractors of any kind safe from any potential dangers that could occur. Understanding these electrical zones and the specific electrical safety guidelines for bathrooms will keep you out of harm’s way.

What are the electrical Bathroom Zones?

There are four different zones in any bathroom. The zonal aspects of each area mainly depend upon the risk in terms of how close water getting close to or potentially touching the electrical supply. If this happened, it could cause damage to the installation but also there is a risk of an electric shock. The four bathroom zones are as follows:

Bathroom Zone 0

Zone 0 is the area inside the bath or the actual shower room, inside the shower basin/tray. If there is no shower basin or tray, zone 0 is 10cm high (from the floor level) extending up to 1.2m around the fixed shower head area.

Bathroom Zone 1

Zone 1 is the area directly above the bath or shower cubicle to a height of 2.25m from the finished floor. Any fitting used in zone 1 must have a minimum rating of IPx4*, which means it is protected against water spray from all directions. If the fitting uses a 240v supply, a 30ma residual current device (RCD) must also be used to protect the circuit in this zone.

Bathroom Zone 2

Zone 2 is similar to Zone 1, in that it requires a minimum of IPX4. Zone 2 refers to the area stretching 0.6m (60cm) outside of the perimeter of the bath and to a height of 2.25m (225cm) from the floor. Furthermore, it is common practice to consider the area around a sink or wash basin, e.g. any area within a 0.6m (60cm) distance of any tap or faucet, to be considered zone 2 as well.

Bathroom Zone 3 (Outside of these Zones)

The normal rules apply outside of these zones. No IP rating is required. All circuits installed in a bathroom must be protected by a 30ma RCD (Residual Circuit Device). Although these days this is common practice and is also a requirement of Part P of the Building Regulations, it is a good idea to double-check this is the case – especially in older bathrooms.

Bathroom Zones and IP Ratings

IP Ratings Explained

In order to fully understand bathroom zones, you should first understand, or at least have a good idea of, IP ratings. The IP stands for International Protection but is more commonly known as Ingress Protection.

An IP rating is simply a number that classifies the level of protection against both liquids and solids in electrical enclosures or pieces of electronic equipment. These ratings are calculated either by the manufacturer or an approved laboratory that carries out specific tests.

The IP number itself consists of two digits. The first digit refers to the level of protection against solid objects e.g. dust. The second digit refers to the level of protection against liquids e.g. water. Typically, The higher the number is, the more robust the level of protection will be.

Please note: You should always ensure that all and any electrical work is carried out by a qualified electrician.