UK BATHROOM ELECTRICAL ZONES – TOWEL RADIATOR INSTALLER WALL CHART

Applies to: Electric & Dual-Fuel Towel Radiators
Regulations: BS 7671 | Building Regs Part P, L, F, C
Always follow manufacturer instructions

        Ceiling
 ───────────────────────
        ZONE 1
 │────────────────────│   ↑ 2.25 m
 │                    │
 │     BATH AREA      │
 │     ZONE 0         │
 │                    │
 └────────────────────┘
      ← 0.6 m →
        ZONE 2

Outside Zones (Preferred Area)

Shower (No Tray – Plan View)

        ZONE 1
   (Radius 1.2 m)
         │
         │
       Shower
         │
         │
      ZONE 0

Zone	Electric / Dual-Fuel Radiator	Key Requirements
Zone 0	❌ NOT PERMITTED	SELV only
Zone 1	⚠️ Restricted	IPX4+, no switches
Zone 2	✔️ Permitted	IPX4+ (IPX5 preferred)
Outside Zones	✔️ BEST PRACTICE	Simplest & safest

IP Ratings (Quick Reference)

• Minimum for bathrooms: IPX4

• Recommended: IPX5 (water jets)

• Never install non-rated products in damp zones

Isolation & Controls (Part P)

✔ Fixed wiring only
✔ Installed by Part P competent person
✔ Double-pole isolation required
✔ Isolation must be outside Zones 0, 1 & 2

Common solutions:

• Switched fused spur outside bathroom

• FCU above door height (outside zones)

❌ No sockets in Zones 1 or 2
❌ No pull cords connected to fixed heaters unless manufacturer approved

Placement Best Practice (All Types)

✔ Outside Zone 2 where possible
✔ Clear airflow above and below radiator
✔ Not behind doors, cabinets, or furniture
✔ Towels must hang freely
✔ Bleed valves accessible (hydronic)

Heating & Part L Compliance

Hydronic Radiators

• Correctly sized for room heat loss

• TRV where applicable

• No dead legs

• Balanced system

Electric / Dual-Fuel

• Rated output suitable for room

• Thermostat not affected by local heat

• Not used as sole heat source unless designed for it

Ventilation (Part F & C)

⚠️ Towel radiators DO NOT replace ventilation

✔ Mechanical extract still required
✔ Free airflow reduces condensation
✔ Never box in towel radiators

Common Site Failures ❌

✘ Installed inside Zone 1 without correct IP
✘ No local electrical isolation
✘ Undersized radiator
✘ Mounted too low (restricted convection)
✘ Non-certified electrical work

INSTALLER RULE OF THUMB

If it’s electric or dual-fuel, install it outside Zone 2 unless there is a strong reason not to.