What are the bathroom zones per BS 7671?

Zone 0 is inside the bath tub or shower tray — only SELV equipment rated IPX7 is permitted. Zone 1 is above Zone 0 up to 2.25m from the finished floor level — equipment must be IPX4 minimum with appropriate protection. Zone 2 extends 0.6m horizontally from Zone 1 — IPX4 equipment with 30mA RCD. Outside zones (beyond Zone 2) has no special IP requirements but 30mA RCD protection is still recommended for all bathroom circuits.

Can I install a socket outlet in a bathroom?

Standard 13A socket outlets are not permitted in Zones 0, 1, or 2. They may be installed outside Zone 2 (more than 0.6m from Zone 1) with 30mA RCD protection — this is typically possible in larger bathrooms. Shaver supply units to BS EN 61558-2-5 (with isolating transformer) may be installed in Zone 2 or outside. SELV sockets (e.g., USB charger at 5V) may be permitted in Zone 2 if appropriately rated.

Is supplementary bonding still required in bathrooms?

Per Regulation 701.415.2, supplementary bonding can be omitted if ALL of the following conditions are met: all circuits in the bathroom are protected by 30mA RCDs, and main protective bonding to all extraneous-conductive-parts is in place. If either condition is not met, supplementary bonding must connect all simultaneously accessible exposed-conductive-parts and extraneous-conductive-parts (pipes, radiators, baths, etc.).

What IP rating do I need for a bathroom light fitting?

Zone 0: IPX7 (protected against temporary immersion). Zone 1: IPX4 minimum (splash-proof from all directions), or IPX5 if water jets are used for cleaning. Zone 2: IPX4 minimum. Outside zones: no specific IP requirement, but IP20 minimum is good practice. For showers with high-pressure jets (e.g., body jets, steam showers), IPX5 is required in Zones 1 and 2.

How are zones measured for a walk-in shower with no tray?

For a shower without a tray, Zone 1 extends 1.2m horizontally from the shower head (measured at the wall) and up to 2.25m from the floor. Zone 2 is 0.6m beyond Zone 1. The 1.2m dimension replaces the tray edge as the boundary of Zone 1. This is important as walk-in showers have larger zone areas than enclosed shower cubicles, affecting where you can position light switches, fans, and other equipment.

TradeCalculator.co.uk

Bathroom Zone Calculator — BS 7671 Section 701

Determine which bathroom zone your equipment is in and the IP rating, voltage, and equipment requirements per BS 7671 18th Edition Section 701.

Installation TypeType of bath/shower

Shower Head Present?Affects zone height calculation

Equipment Horizontal Distance

From edge of bath/tray to equipment

Equipment Height from Floor

Height of equipment above finished floor

How We Calculate This

This calculator determines the bathroom zone for a given equipment position based on BS 7671 18th Edition Section 701 zone dimensions.

Zone Dimensions

Zone 0: Inside the bath tub or shower tray
Zone 1: Above Zone 0 to 2.25m from floor, within the perimeter of the bath/tray
Zone 2: 0.6m horizontally from Zone 1 boundary
Above ceiling: If ceiling is below 2.25m, space above is Zone 1 or 2
Walk-in shower: Zone 1 extends 1.2m from shower head
Window in zone: Window recess within a zone is the same zone