Bathroom lighting zones and IP rating checker

What are bathroom lighting zones?

Bathroom lighting zones are the areas around a bath or shower defined in Section 701 of BS 7671, the IET Wiring Regulations. Zone 0 is inside the bath or shower tray, Zone 1 is the space directly above it up to 2.25 m from the floor, and Zone 2 is the 0.6 m band beyond that. Each zone sets a minimum IP rating for any light installed there.

The closer a fitting is to someone standing wet, the more water protection it needs, and in Zone 0 it must also run at safety extra-low voltage (SELV). Everywhere else is outside the zones, where Section 701 gives no IP figure but steam and condensation still matter.

How to use the bathroom lighting zones checker

1. 01Layout: enter the room width and length in metres. Pro users can pick a preset such as Small En-suite (2.0 m × 1.5 m) or Family Bathroom (3.5 m × 3.0 m).
2. 02Furnish: drag the bath (1.7 m × 0.75 m), shower tray (0.9 m × 0.9 m), basin, toilet, door and window onto the plan. Items snap to a 10 cm grid; select one to rotate it or type its real size.
3. 03Lighting: drag fittings from the library (IP65 downlight, IP20 pendant, IP44 linear, IP44 wall light, IP67 SELV niche strip) or add your own with any rating from IP20 to IP68 and a SELV tick box.
4. 04Set the mounting height with the slider (0 to 3.5 m) and switch on Show Zones. Each fitting's badge turns green for pass or red for fail, and the inspector panel gives the reason.
5. 05Export: review the on-screen compliance report and fixture schedule. Verify Compliance re-runs every fitting on NR Lighting's servers; Pro users can add project details and download a PDF report.

The method: how the zone and IP rating are decided

Zone = horizontal distance from the bath or tray edge × height above the finished floor. Inside the footprint, up to 2.25 m: Zone 1. Up to 0.6 m beyond the edge, up to 2.25 m: Zone 2. Inside the tray itself: Zone 0. Minimums: Zone 0 IPX7 + SELV 12 V; Zones 1 and 2 IPX4.

For each fitting the checker takes its position and mounting height, tests it against every bath and shower tray on the plan, and reports the most demanding zone it falls into. It passes when its IP rating is at least the zone minimum and, in Zone 0, when it is marked SELV. Results update as you drag.

Two conventions are deliberately cautious. A 0.6 m radius around a wash basin is treated as a splash area with the Zone 2 requirement, although Section 701 defines no zones around basins. The band from 2.25 m to 3.0 m directly above a bath or shower is also kept in Zone 2, so a ceiling downlight over a shower is asked for IP44.

What do IP44, IP65 and IP67 mean?

An IP rating has two digits from BS EN 60529: the first for solids and dust, the second for water. Section 701 only cares about the second, which is why it writes IPX4 and IPX7. IP44 is splash-proof and satisfies IPX4 for zones 1 and 2; IP65 is dust-tight and jet-proof, the usual choice over a shower; IP67 survives temporary immersion and, with SELV, is what Zone 0 needs. IP20 has no water protection and belongs outside the zones.

Worked example: a 3.0 m × 3.0 m bathroom

Take the default 3.0 m × 3.0 m room with a 2.4 m ceiling. Place the 1.7 m × 0.75 m bath along the back wall, the 0.9 m × 0.9 m shower tray in a corner and the basin on the opposite wall, then add four fittings.

• IP65 downlight at 2.4 m over the shower tray: inside the footprint and above 2.25 m, so Zone 2. Needs IP44; passes.
• IP44 wall light at 1.6 m, 0.4 m from the basin centre: inside the basin splash area, so Zone 2. Needs IP44; passes.
• IP20 pendant, lowest point 2.0 m, 0.5 m from the bath edge: Zone 2. Fails with 'IP20 is below required IP44'. Moved to 0.7 m from the bath it is outside the zones and passes.
• IP67 SELV niche strip at 0.0 m inside the shower tray: Zone 0. Needs IP67 and SELV; passes. Untick SELV and it fails with 'Zone requires SELV'.

Limitations, and when to involve a lighting designer

The checker gives indicative design values, not a compliance certificate. It models baths and trays as rectangles, does not extend Zone 1 to a shower head fixed above 2.25 m or to the 1.2 m radius around a shower without a tray, and knows nothing about RCD protection, supplementary bonding or the ceiling void. Layouts are not saved; Verify Compliance sends fitting positions and heights to NR Lighting's servers for a second check and nothing is published.

I bring a lighting designer in when the bathroom is part of a larger scheme, when a client wants a pendant or decorative wall lights close to the bath, or when a hotel or spa needs consistent colour temperature, glare control and dimming across many rooms. In England, adding or altering a circuit within a bathroom zone is notifiable under Part P, so the installation should be carried out and certified by a registered electrician. To resolve zones, fittings and controls together, get in touch.