Water and electricity are a dangerous combination. To manage the risks in bathrooms and shower rooms, BS 7671 (the IET Wiring Regulations) divides bathrooms into zones that determine what electrical equipment can be installed and what IP rating it must achieve.
The Three Bathroom Zones
Zone 0
The interior of the bath or shower basin itself. Only equipment specifically designed for use in this zone (typically SELV — Separated Extra Low Voltage — products such as spa pumps) can be installed here. IP rating of at least IP67 required.
Zone 1
The area above the bath or shower tray, up to 2.25 metres above the floor. Equipment must be rated at least IPX4 (splash-proof). Shaver sockets, light fittings and extractor fans installed in Zone 1 must meet this standard. Shower units are typically installed here.
Zone 2
An area extending 0.6 metres horizontally from Zone 1, and up to 2.25 metres above the floor. Equipment must be rated IPX4 minimum. Shaver sockets and bathroom lighting in Zone 2 must be compliant.
Outside the Zones
Beyond Zone 2, normal electrical accessories can be installed — sockets, switches, heated towel rails. However, some older guidance specified a Zone 3 extending a further 2.4 metres; while this is no longer a formal zone in BS 7671, many electricians still apply caution in this area.
Common Bathroom Electrical Work
Extractor fans — must be Zone 1 or 2 compliant if installed within the zones. Usually wired to a fused spur or lighting circuit and must activate automatically via humidity sensor or run-on timer.
Shaver sockets — must be installed in Zone 2 or beyond and contain an isolation transformer to prevent shock risk.
Downlights — fire-rated IP65 downlights are suitable for bathrooms. Standard downlights with no IP rating are not suitable in wet areas.
Heated towel rails — typically connected via a fused connection unit (fuse spur) outside Zone 2. Must not be manually switched; pull-cord or remote control is acceptable.
Why Use a Qualified Electrician for Bathroom Work?
Incorrect electrical work in bathrooms is one of the most dangerous mistakes a homeowner can make. All electrical work in bathrooms is notifiable under Part P and must be carried out by a registered electrician or notified to Building Control.
Onyx Electrical Solutions is NICEIC registered and experienced in all types of bathroom electrical work across Greater Manchester. Call 07000 000000 for a free quote.