Bathroom Zones UK — BS 7671 Section 701

UK bathroom zone guide — Zone 0, 1, 2, and Outside Zones with minimum IP ratings, socket rules, RCD requirements, and supplementary bonding per BS 7671 Section 701.

What Are the UK Bathroom Zones? Quick Answer

BS 7671 Section 701 divides UK bathrooms into four zones by proximity to water: Zone 0 (inside bath/shower basin, IPX7 + 12V SELV only), Zone 1 (above bath/shower to 2.25m, IPX4 minimum), Zone 2 (0.6m beyond Zone 1, IPX4 minimum), and Outside Zones (IP20 OK but IPX4 recommended). All bathroom circuits require 30mA RCD protection. Standard 13A sockets are NOT permitted in Zones 0, 1, or 2 — shaver sockets (BS EN 61558-2-5) are allowed in Zone 2 and beyond. Supplementary bonding is NO longer mandatory under Amendment 2 if RCD protection and main protective bonding are in place.

Bathroom Zones at a Glance

ZoneWhereMin IPSockets?Typical use
Zone 0Inside bath/shower basinIPX7 + SELV 12V onlyNo12V LED spot, jacuzzi pump
Zone 1Above bath/shower to 2.25m heightIPX4 (IPX5 if jets used)NoShower downlight, extractor
Zone 20.6m beyond Zone 1 boundaryIPX4Shaver only (BS EN 61558-2-5)Wall lights, shaver socket, IPX4 fan
Outside ZonesRest of bathroomIP20 (IPX4 recommended)Yes (with 30mA RCD)Switches, timers, 13A sockets

BS 7671 Section 701 — What It Covers

BS 7671:2018+A2:2022 Section 701 defines special-location requirements for "rooms containing a bath or shower." The section recognises that water and electricity are a dangerous combination and establishes zones based on the risk of water contacting electrical equipment. It applies to all rooms where a bath or shower is installed, including wet rooms and en-suites.

Key Regulations in Section 701

  • 701.32.1-3 — Zone definitions: Geometric boundaries of Zones 0, 1, and 2.
  • 701.411.3.3 — RCD protection: All circuits serving the location require 30mA RCD.
  • 701.411.3.4 — Bonding: Main protective bonding required to MET.
  • 701.415.2 — Supplementary bonding: Required unless Amendment 2 exemption conditions are met.
  • 701.512.2 — Equipment IP ratings: Minimums per zone (Zone 0 IPX7, Zones 1-2 IPX4).
  • 701.512.3 — Switchgear location: Switches not permitted in Zones 0, 1, 2 (except specific exemptions).
  • 701.514 — Socket outlets: 13A sockets prohibited in Zones 0, 1, 2; shaver sockets per BS EN 61558-2-5 allowed in Zone 2+.
  • 701.55 — Current-using equipment: Fixed equipment in Zone 1 must be IPX4 and permanently connected.

Amendment 2 update (effective Sept 2022): The mandatory supplementary bonding requirement was relaxed. If a bathroom circuit has 30mA RCD protection and main protective bonding is in place, and extraneous-conductive-parts meet the required resistance, supplementary bonding is NOT required. Older installations and those not meeting the three conditions still require it under 701.415.2.

Zone-by-Zone Rules — Detailed Reference

Zone 0 — Inside the Bath or Shower Basin

The volume inside the bathtub or shower tray itself. For showers without a basin, Zone 0 does not exist — the shower area starts at Zone 1.

  • Minimum IP: IPX7 (temporary immersion protection).
  • Voltage: SELV only, maximum 12V AC or 30V DC.
  • Equipment permitted: SELV luminaires (12V LEDs), whirlpool pumps (if intrinsically SELV).
  • Sockets: Prohibited.
  • Switches: Prohibited.

Zone 1 — Above the Bath/Shower

The volume directly above Zone 0 up to 2.25m from the finished floor level, OR within 1.2m horizontal radius of a shower head where no basin exists. The most common zone for downlights and extractor fans.

  • Minimum IP: IPX4 (splashing). IPX5 if water jets are used for cleaning.
  • Voltage: Full mains (230V) permitted for fixed equipment.
  • Equipment permitted: Fixed, permanently-connected luminaires; extractor fans; towel rails (IPX4+); electric showers.
  • Sockets: Prohibited.
  • Switches: Only pull-cord switches permitted; wall switches not allowed.
  • Portable appliances: Not permitted.

Zone 2 — 0.6m Beyond Zone 1

The volume 0.6 metres horizontally outward from the Zone 1 boundary, at the same height range. Covers adjacent wall spaces.

  • Minimum IP: IPX4.
  • Voltage: Full mains permitted.
  • Equipment permitted: Wall lights, shaver sockets (BS EN 61558-2-5), IPX4 extractor fan timers/humidistats.
  • Sockets: Shaver sockets only; no 13A sockets.
  • Switches: Not permitted in Zone 2 itself; must be outside zones or pull-cord.

Outside Zones — Rest of the Bathroom

Everywhere else in the bathroom, beyond Zone 2 horizontal and above 2.25m height.

  • Minimum IP: IP20 is technically compliant but IPX4 is trade-recommended.
  • Voltage: Full mains permitted with 30mA RCD.
  • Equipment permitted: Standard luminaires, switches, thermostats, 13A sockets.
  • 13A Sockets: Permitted provided 30mA RCD protection and ideally 3m from Zone 1.
  • Towel rail switches: Typically mounted outside zones at the bathroom door.

Common Bathroom Equipment — IP Rating & Zone Reference

Typical UK bathroom electrical equipment and where it can go per BS 7671 Section 701.

EquipmentTypical IP RatingPermitted ZonesNotes
Fire-rated LED downlightIP44 or IP65Zones 1, 2, outsideIP65 preferred for shower area
12V SELV spot in showerIPX7Zone 0, 1Only SELV in Zone 0
Extractor fan (domestic)IP44Zones 1, 2, outsideTimer/humidistat models for Zone 1
Shaver socketIP44Zone 2, outsideBS EN 61558-2-5 isolating transformer required
13A socket outletIP20 (or IP44)Outside zones only (ideally 3m+)30mA RCD mandatory
Electric shower (8-10.8kW)IP44Zones 1, 2Pull-cord isolator outside Zone 1
Electric heated towel railIPX4Zone 2, outsideFlex outlet, no plug; SELV in Zone 1
Underfloor heatingIPX7 (in slab)Zones 0, 1, 2 (floor-embedded)30mA RCD; thermostat outside zones
Mirror light with shaver socketIP44Zone 2, outsideIntegrated BS EN 61558-2-5 transformer
Pull-cord ceiling switchIP20 (IP44 wet rooms)Zones 1, 2, outsideOnly switch type permitted in Zone 1

Socket and RCD Rules in UK Bathrooms

13A Sockets

  • Zones 0, 1, 2: Prohibited. No 13A sockets allowed under any conditions.
  • Outside zones: Permitted, but ideally located at least 3 metres from the Zone 1 boundary.
  • Protection: 30mA RCD required on all bathroom circuits per BS 7671 Reg 411.3.3.
  • Typical location: On the wall near the door or above a vanity unit outside all zones.

Shaver Sockets (BS EN 61558-2-5)

  • Standard: Must comply with BS EN 61558-2-5 (isolating transformer built in).
  • Zone 2 and outside: Permitted.
  • Zone 1: NOT permitted (despite having an isolating transformer).
  • Zone 0: Prohibited.
  • Typical use: Mirror-mounted for shavers and toothbrush chargers.

RCD Protection Requirements

  • 30mA RCD on ALL bathroom circuits per BS 7671 Reg 411.3.3. Non-negotiable, regardless of zone.
  • RCBO preferred — a single RCBO per circuit avoids nuisance tripping across multiple circuits.
  • Type AC RCD insufficient for modern electronics: Type A (or Type F) recommended for circuits supplying electronic loads (LED drivers, fan controllers).
  • Test button: RCDs must be tested twice yearly per BS 7671 guidance.

Supplementary Bonding — Amendment 2 Update

BS 7671 Amendment 2 (effective September 2022) significantly relaxed the supplementary bonding requirement for UK bathrooms. Understanding when bonding IS and IS NOT required is critical for modern installations.

When Supplementary Bonding is NOT Required (Amendment 2 exemption)

Bonding is NOT required if ALL three conditions are met:

  1. All final circuits serving the bathroom are 30mA RCD protected.
  2. Main protective bonding is in place from the consumer unit to all extraneous-conductive-parts (water pipes, gas pipes, etc.) entering the building.
  3. Extraneous-conductive-parts in the bathroom (metal pipes, radiators) meet the prescribed resistance requirement to the main earthing terminal (typically <50kΩ for TN systems).

When Supplementary Bonding IS Required

  • Older installations without RCD protection on bathroom circuits.
  • TT installations with high earth electrode resistance (resistance to MET >50kΩ typical).
  • Non-compliant main bonding — if main bonding is undersized or missing, supplementary bonding fills the gap.
  • When extraneous-part resistance fails the test (>50kΩ TN, lower for TT).

What to Bond (if required)

  • Metal pipework (hot water, cold water, central heating flow/return).
  • Metal bath tubs (increasingly rare — most UK baths are plastic or steel-enamel, but check with a resistance test).
  • Metal radiators and towel rails.
  • Metal shower trays or drainage waste pipes (again, rare but test).
  • Cable: minimum 4mm² green-yellow single, clamped via BS 951 clamps.

Worked Examples — Real UK Bathroom Layouts

Example 1: Family Bathroom with Shower-Over-Bath

Layout: 2.2m x 3m bathroom with a bath (shower head over bath), WC, and basin. Ceiling 2.4m high.

  • Zone 0 (inside bath): No electrical.
  • Zone 1 (above bath to 2.25m): 2x Aurora EFD Pro IP65 downlights over the bath.
  • Zone 2 (0.6m outside bath): 1x downlight; Manrose SF100T IPX4 extractor fan with integrated timer.
  • Outside zones (by door): Light switch and IPX4 shaver socket above vanity unit.
  • Circuits: Lighting on 6A MCB + 30mA RCD; extractor on lighting circuit; no 13A socket (would go outside bathroom).

Example 2: Walk-In Shower En-Suite (No Bath)

Layout: 1.8m x 2.5m en-suite with walk-in shower enclosure, WC, basin. No bath. Shower head 2.1m above floor.

  • Zone 1 (1.2m radius from shower head): IP65 LED downlight above shower; IPX4 extractor in ceiling.
  • Zone 2 (0.6m beyond Zone 1 radius): 1x IP44 wall light above basin mirror.
  • Outside zones: Pull-cord switch for extractor by door; light pull-cord or outside wall switch; no 13A socket.
  • Electric shower: 9.5kW Mira Sport — 10mm² T&E, 45A MCB dedicated circuit, 30mA RCBO, pull-cord isolator just outside Zone 1.

Example 3: Wet Room with Floor Drain

Layout: 2.4m x 2.4m wet room with tiled floor to drain, overhead shower, no bath or basin (basin in adjacent room).

  • Zone 1 (1.2m radius from shower head): IP65 or IP67 LED downlights preferred due to wash-down environment.
  • Zone 2: IP44 extractor fan with humidistat.
  • Outside zones: Only at the room entry door — switches and any 13A socket.
  • Upgrade from minimum: Specify IP65 throughout for cleanability. Underfloor heating IPX7-rated cable (standard for wet areas) with RCBO-protected thermostat outside the wet zones.

Common Bathroom Zone Installation Mistakes

  • 13A socket too close to Zone 1. Section 701 prohibits 13A sockets in Zones 0-2. Best practice is 3m+ from Zone 1 boundary. Placing "just outside Zone 2" is technically compliant but inspectors may flag it as imprudent.
  • Wall switch in Zone 2. Only pull-cord switches are permitted in Zones 1 and 2. A wall-mounted rocker switch must be outside all zones — typically on the outside wall by the door.
  • Shaver socket in Zone 1. Despite having an isolating transformer, BS EN 61558-2-5 shaver sockets are only permitted from Zone 2 onwards.
  • Missing 30mA RCD. Section 701 requires 30mA RCD on every bathroom circuit without exception. Skipping on a fixed-equipment circuit (e.g. towel rail) is a compliance failure.
  • Assuming Amendment 2 removes all bonding. Supplementary bonding may still be required on TT installations, older installs, or where extraneous-part resistance fails the test. Verify conditions before omitting.
  • IP44 in wet-room Zone 1. IP44 is the technical minimum, but for walk-in wet rooms where the entire ceiling may be in Zone 1 and subject to spray, IP65 is trade practice for reliability and cleanability.
  • Towel rail plugged in via 13A socket. Bathroom towel rails must be permanently connected (flex outlet, not plug and socket) if in Zones 1-2. Plug-and-play towel rails are only legal outside zones.
  • Counting floor level incorrectly. Zones measure from finished floor level (FFL), not the sub-floor or the top of tiles if higher. Zone 1 vertical extent is 2.25m above FFL.

Frequently Asked Questions

Related IP Rating Guides

IP Rating Chart UK (all ratings)

Complete IP00 to IP69K reference.

IP44 Rating Explained

BS 7671 minimum for Zone 1-2.

IP65 Rating Explained

Trade-standard upgrade for wet-area reliability.

Shower Circuit Calculator

Cable size, MCB, voltage drop for 7.5-10.8kW showers.

Free: BS 7671 Quick Reference Card

Max Zs values, diversity factors, cable ratings, voltage drop — one printable page. Plus occasional emails with calculator updates and useful tips.

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