Bathroom lighting is the most overlooked element in renovation planning — and the one that makes the biggest difference to how the finished space actually feels to use. It’s also one of the most technically constrained areas of the home, subject to building regulations that govern where different types of lighting can be installed.
This guide covers how to plan bathroom lighting correctly, from zone regulations to layered lighting design.
UK Bathroom Lighting Zones
In the UK, building regulations divide the bathroom into IP (Ingress Protection) zones that determine which light fittings can be used where. These are not optional guidelines — they are legal requirements.
- Zone 0 — Inside the bath or shower enclosure. Requires IP67 minimum. Very few domestic fittings are rated for this zone.
- Zone 1 — Directly above the bath or shower, up to 2.25m above the floor. Requires IP45 minimum (IP65 recommended). All fittings must be suitable for use in wet areas.
- Zone 2 — 0.6m outside the bath/shower edge and up to 2.25m above the floor. Requires IP44 minimum. This covers the area around the basin in most bathrooms.
- Outside zones — No specific IP requirement, though general best practice is IP44 for any bathroom fitting.
When purchasing bathroom light fittings, check the IP rating. Fittings rated below the zone requirement cannot be used in that area and may be unsafe and invalidate your home insurance.
The Three Layers of Bathroom Lighting
Good bathroom lighting requires three layers, each serving a different purpose.
Ambient Lighting
The base layer — general illumination from the ceiling. Recessed downlights are the most common choice in contemporary bathrooms, providing clean, unobtrusive light from above. Position them symmetrically and ensure they’re spread evenly across the room, not clustered over the bath or shower.
A dimmer switch (where regulations allow) transforms the ambient layer — full brightness for cleaning and grooming, low brightness for bathing in the evening.
Task Lighting
Lighting specifically for the mirror and basin area. This is where most bathroom lighting schemes fail — a ceiling downlight directly above the mirror creates shadows under the eyes and chin that make shaving, applying makeup, and skincare routines difficult.
The correct solution is side lighting — a vertical light fitting on either side of the mirror, or a horizontal bar above the mirror wide enough to spill light to the sides. The light source should be at face height or just above it, so it illuminates the face evenly from the front rather than casting shadows from above.
If you cannot fit side lighting, a wide mirror with integrated edge lighting (lit from the sides of the mirror body rather than behind it) is the next best option.
Accent and Atmosphere Lighting
Optional but impactful. Subtle indirect lighting — from LED strip behind a floating shelf, uplight from a freestanding bath, or a small table light on a ledge — adds warmth and depth to a bathroom that would otherwise feel flat at low light levels.
Colour Temperature
The colour temperature of bathroom lighting affects how both the room and your face appear in the mirror.
- 2700K–3000K (warm white) — Flattering, warm, and suitable for relaxing baths. Can make some skin tones appear warmer than they are in daylight.
- 3500K–4000K (neutral white) — More accurate colour rendering. Better for grooming tasks where accurate colour assessment matters.
A good compromise is 3000K for ambient lighting and 3500K for task lighting around the mirror, achieved by using two separate circuits.
The Mirror Question
A good mirror in the right position, well-lit, is worth more to the daily experience of a bathroom than almost any other element. When choosing a bathroom mirror, consider:
- Size — It should be proportional to the basin vanity and wide enough to illuminate the full face area
- Lighting integration — A mirror with integrated LEDs removes the need for separate task fittings
- Anti-fog — Heated mirror pads prevent condensation during and after showers
Browse Cortenvale’s bathroom range at cortenvale.com/collections/bathroom.