Zones and IP ratings, plainly
Zone 0 is inside the bath or shower tray itself. Anything here must be low voltage and rated IPX7.
Zone 1 is directly above the bath or shower up to 2.25 m. Fittings need to be at least IPX4, and in practice we fit IP65 here.
Zone 2 extends 0.6 m beyond zone 1 and around a basin. IPX4 is the minimum, and again IP65 is the sensible standard.
Outside the zones, the requirement relaxes, but a bathroom is still a humid room and we would not fit an unrated decorative fitting where steam collects.
All of it is notifiable work in a special location. Our own electrician carries it out and issues the certificate with the job.
Layer the light rather than flooding it
Ambient layer: the general light that lets you clean the room and see where you are going. Usually recessed downlights or a flush ceiling fitting.
Task layer: light aimed at faces, not at the top of heads. This is mirror lighting, and it is the layer most bathrooms get wrong.
Accent layer: a strip under a vanity, a niche light in the shower, or a low-level nightlight. Small spend, disproportionate effect.
The rule we use on site is simple. If the only light in the room is above you, everything you do at the mirror happens in your own shadow.
What lighting costs to install
Supply-and-fit ranges for a typical Berkshire bathroom, assuming the work is part of a wider refurbishment so the ceiling is already accessible.
| Item | Supply cost | Fitted cost each | Notes |
|---|---|---|---|
| IP65 fire-rated downlight | £12-£35 | £45-£85 | Allow 4-6 in a family bathroom |
| LED mirror with demister | £90-£350 | £150-£450 | Needs a fused spur behind |
| Illuminated mirror cabinet | £180-£600 | £250-£750 | Check depth against door swing |
| Shower niche LED strip | £40-£120 | £120-£260 | Must be IP65 and low voltage |
| Dimmer module (LED-rated) | £25-£70 | £70-£150 | Only with dimmable drivers |
| Full rewire of bathroom circuit | - | £350-£700 | Where existing wiring is unsuitable |
Colour temperature and dimming
Around 3000K is our default. It is warm enough to feel like a home rather than a clinic, but clean enough to see colours properly for shaving or make-up.
4000K suits very white, minimal schemes and north-facing rooms, but it can feel harsh with warm-toned marble-effect tiles.
Mixing colour temperatures in one small room is the most visible mistake you can make. Match the mirror light to the downlights.
If you want dimming, specify dimmable drivers at the outset. Retrofitting a dimmer to non-dimmable LED fittings causes flicker and buzz, and cannot be fixed at the switch.
Mirror lighting that flatters
Light from both sides of the face at roughly eye level is the gold standard. It removes shadows under the eyes and chin.
Where side lighting is not practical, a backlit mirror with an even diffused edge is the next best thing, and it is what most of our customers choose.
A downlight directly in front of the mirror rather than directly above it improves things considerably at no extra cost.
Demister pads are a genuine quality-of-life upgrade in a room with a shower and cost very little to add during the fit.
Frequently asked questions
What IP rating do I need for bathroom lights?
IPX4 is the minimum in zones 1 and 2, though we fit IP65 as standard because it copes far better with steam over time. Zone 0 requires IPX7 low-voltage fittings.
How many downlights does a bathroom need?
Four to six for a typical family bathroom, positioned to light the floor, mirror and shower rather than spaced evenly for their own sake.
Can I have a dimmer in a bathroom?
Yes, provided the fittings and drivers are dimmable and the dimmer itself is located appropriately. Specify it at the planning stage rather than afterwards.
Does bathroom lighting work need certifying?
Yes, it is notifiable work in a special location. Our own electrician carries it out and issues the certificate as part of the job.
Are LED mirrors worth it?
For most people, yes. They provide the face-level task light a ceiling downlight cannot, and the demister versions solve the fogging problem completely.