Bathroom Electrical Installation

The BS 7671 wiring regulations divide bathrooms into zones based on proximity to water sources. Zone 0 is inside the bath or shower tray, Zone 1 is directly above the bath or shower to a height of 2.25 m, and Zone 2 extends 0.6 m beyond Zone 1. Each zone has strict requirements for the IP rating of any electrical equipment installed. Outside these zones, standard fittings can be used, but we always recommend a higher IP rating for longevity in damp environments.

Building Regulations (Approved Document F) require mechanical extract ventilation in any bathroom that does not have an openable window providing adequate ventilation. Even if you have a window, we strongly recommend a fan to reduce condensation, damp, and mould. Timer-delay and humidistat fans are the most effective options.

Standard 13A sockets are not permitted within 3 metres of a bath or shower in the UK. The only socket type allowed inside a bathroom is a shaver supply unit conforming to BS EN 61558-2-5, which provides electrical isolation. If you need charging points, a shaver socket with a USB outlet is the safest option.

In Zone 1 (directly above the bath or shower), light fittings must be rated at least IPX4 (splash-proof). In Zone 0, they must be IPX7 (submersible). In Zone 2, IPX4 is again the minimum requirement. Outside the zones, standard fittings are technically permitted, but we recommend at least IP44 throughout the bathroom for safety and longevity.

Yes. Installing new circuits, such as a shower circuit or extractor fan, in a room containing a bath or shower is notifiable under Part P. We carry out and test the work to BS 7671 and provide an Electrical Installation Certificate; as notifiable work it also needs registering with Building Control, and we’ll advise you on how that’s handled for your job.