§701 — Bathrooms and Shower Rooms

Section 701 of NEN 1010 (NEN-EN-IEC 60364-7-701) specifies the additional requirements for electrical installations in rooms with a bath or shower. The ratio: water + body with low skin resistance + bare feet on a conductive floor = significantly lower threshold above which contact with voltage becomes lethal. The prescribed UL (touch voltage limit) drops from 50 V to 25 V once the body is normally wet.

Zones (§701.32)

Zone	Definition	Restriction
0	Inside the bathtub/shower basin (water volume)	SELV ≤ 12 V AC / 30 V DC; IPX7.
1	Above Zone 0 up to 2.25 m height; vertical plane around the bathtub/shower	SELV ≤ 25 V AC or fixed 230 V lighting with IPX4, no wall socket.
2	0.6 m horizontally outside Zone 1, up to 2.25 m	IPX4; wall socket only if SELV or via isolation transformer.
(3)	Abolished in IEC 60364-7-701:2019. Sometimes still mentioned in older literature.

⚠️ Since NEN 1010:2020, Zone 3 has been abolished — it was deemed too leniently interpreted. Outside Zone 2, general §411 protection now applies, provided §701.415.2 (supplementary bonding) is complied with.

Earth Leakage Protection (§701.411.3.3)

All final circuits entering the bathroom (lighting, wall socket, heating, shower pump, bathroom furniture, mechanical ventilation) must be protected by a 30 mA residual current device (RCD) (type A or better).

Exception: SELV circuits ≤ 12 V AC / 30 V DC may be without RCD, as the voltage level itself is already below the threshold.

Practical note: in a new-build home, the entire bathroom is on its own RCD circuit (living room separate) so that a leakage current in the shower does not trip the refrigerator. Different RCD circuits must not share the N-conductor — a common installer error that causes uncontrolled N-currents and trips the main breaker on the most inconvenient morning.

Supplementary bonding (§701.415.2) — supplementary bonding

All conductive parts within zones 1 and 2 must be interconnected via a supplementary bonding conductor.

In practice, this means:

The bathtub itself (metal) or bathtub frame (conductive).
The heating radiator in the bathroom.
Water, gas, and heating pipes entering the room.
Metal washing machine connection (if present).
Steel structural profiles, if conductive and accessible.

Using a green/yellow bonding conductor ≥ 4 mm² (Cu), connected to:

either the main earthing rail (MET),
or a local LET (local equipotential terminal) in the bathroom, which in turn is connected to the main earthing rail.

The ratio represents a potential equalization: in the event of an insulation fault in the washing machine that carries the chassis to +230 V and simultaneously has not yet tripped the RCD, the entire bathroom rises to the same potential instead of 230 V existing between the washing machine and the heating pipe. Result: no current through the body.

Continuity testing ≤ 0.3 Ω between each bonding point and the main earthing rail.

Materials & IP Rating (§701.512)

Component	Min IP	Note
Lighting zone 1	IPX4	Splash-proof; ceiling-mounted LED spots usually IP44.
Lighting zone 2	IPX4	Same.
Wall socket zone 2	IPX4	Shaver socket via transformer OR SELV 25 V.
Switch zone 0/1	not permitted	Pull-chain switch allowed (cord operation).
Infrared heating	IPX4	Permitted in zone 2; in zone 1 only fixed, IP44.
Shower radio mounted	IPX4	Usually IP44 + only on mains via SELV.

Underfloor heating in zone 1

Electrical underfloor heating in the shower zone requires:

Grounding screen in the matting; connected to MET or LET.
RCD 30 mA on the circuit (as for all bathroom circuits).
Additional bonding with the grounding screen → the zone 1 floor becomes part of the equipotential bonding.
Floor thermostat installed outside zone 1 (often in the hallway or near the switching equipment).

Mechanical ventilation (WTW / box fan)

A dedicated final circuit with a 30 mA RCD; the unit itself should preferably be mounted above 2.25 m (= outside all zones). The sealing density at the flexible ducts must not lead to water ingress into the motor — IP44 for the fan itself.

Inspection (§701 in NEN 1010 §6)

Upon handover, inspect:

Visual — IP classes, mounting heights, no wall socket in zone 0/1.
Continuity of PE and supplementary bonding — all metal parts ≤ 0.3 Ω to the main earthing terminal.
RCD test — tripping time ≤ 40 ms at 5 × IΔn.
Insulation resistance ≥ 1 MΩ between L–PE and N–PE at 500 V DC.
Touch voltage simulation — should not exceed 25 V.

Renovation versus new construction

NEN 1010 applies to new installations. In renovation, the old installation remains strictly formal permitted, but:

As soon as the installer adds or replaces "something", that extension falls under the current standard.
Legally (Building Decree 2012 art. 6.8), a renovation must maintain at least the legally achieved level — a worse installation is not permitted.
Insurers require NEN 1010 compliance at the time of damage claims; in practice, this is the binding pressure.

Recommendations for clients: a 30 mA RCD update + minimal supplementary bonding is a renovation costing a few hundred euros that makes the entire house suddenly safer.

Common Errors

Wall socket in Zone 1 "behind a splash guard". Not permitted — only a hair-cutting socket via a separating transformer SELV.
No additional earthing on the CV radiator. The radiator often carries potential from the CV installation; without earthing, this floats to every voltage of the house installation.
30 mA RCD type AC. No DC detection; in a modern installation with inverter converters/charging boxes, this is insufficient. NEN 3140 rejects this.
Floor heating without earth screen in Zone 1. In the event of an insulation fault, L goes directly to the wet floor.
N-conductors shared between bathroom RCD and living room RCD. Unexplained tripping, often after months.

Bathrooms and Shower Rooms