As a starting point, space LED downlights at roughly half your ceiling height apart — a 2.4m ceiling wants them about 1.2m apart. That single rule gets you most of the way to an even, shadow-free ceiling.
The rest is fire rating, which is not optional, and beam angle, which is what separates a room that looks designed from a room that looks like an airport.
The mistake we see every week at the counter is somebody buying twelve downlights for a room that needs six, because they've counted on brightness instead of spacing. Twelve is not twice as good. Twelve is a flat, overlit ceiling with no shadows anywhere and a bigger bill.
1. How many, and how far apart
Start with the half-ceiling-height rule, then adjust:
- 2.4m ceiling — roughly 1.2m spacing
- 2.7m ceiling — roughly 1.35m spacing
- 3m ceiling — roughly 1.5m spacing
Then keep the outer row about 600–750mm off the walls. Too close and you scallop the walls with bright arcs; too far and the room's edges go dark and it feels smaller than it is.
Trade Tip: set out downlights to the room, not to the joists. People discover a joist where a light should go and shuffle the whole grid to suit — and you can see it from the doorway forever. Mark your ideal positions first, then deal with the joists: a fitting can move 50–75mm without anyone noticing, and where it genuinely can't, that's what a different fitting position or a small timber noggin is for.
For a kitchen, don't centre them in the room. Line them over the front edge of the worktop, so you're lit from in front rather than standing in your own shadow — our kitchen lighting guide goes deeper on that.
2. Fire rating is not an upgrade
Cutting a hole in a ceiling cuts a hole in that ceiling's fire resistance. Where the ceiling separates floors — which in a normal house means every downlight in a ground-floor ceiling with rooms above — that resistance has to be restored.
Two ways to do it, and they're different products:
A fire-rated fitting has an intumescent seal built in that expands in a fire and closes the hole. One part, done at installation.
The Knightsbridge VFRDGICW is a fire-rated GU10 downlight, 50W max, 230V, IP20, in white. The VFRDGICCBR is the same in brushed chrome, and the VFRSGICB is the brass tilt version — fire-rated, IC compatible, twist lock, 105mm recess.
A fire hood is a separate intumescent cover fitted over a non-fire-rated downlight from above. Its place is retrofit — an existing installation where replacing every fitting isn't practical.
The Knightsbridge FR150 is a 150mm fire hood, 60-minute rated, intumescent, CE and UKCA certified.
Trade Tip: fire-rated fittings are typically also rated for direct contact with insulation — worth knowing, because the other common loft mistake is pulling insulation back from around downlights to "let them breathe" and leaving a cold patch above every fitting. Check the fitting's own rating; if it's IC-rated, the insulation stays where it belongs.
3. GU10 or integrated LED
A GU10 fitting takes a replaceable lamp. When it fails you buy a lamp for a couple of pounds. You can also change colour temperature later by changing lamps, which is genuinely useful if you get it wrong first time.
An integrated LED has the LED built in. Slimmer, often neater, sometimes brighter for the size — but when it dies, the whole fitting comes out of the ceiling.
We stock GU10, and that's a deliberate position: in a house with fifteen downlights, replaceable lamps is the difference between a two-pound job and a ladder, a ceiling and a shopping trip.
Tilt fittings like the VFRSGICB earn their place at the edges of a room, aimed at artwork, a splashback or a bookcase. Used across a whole ceiling they just look uneven.
4. Lumens, not watts
Watts measure consumption. Lumens measure light. With LED the two have completely decoupled, and the old "60W bulb" shorthand no longer tells you anything useful.
As a rough guide for a domestic downlight, 400–500 lumens each is a sensible working figure — bright enough for general lighting without turning a lounge into a showroom. A kitchen worktop wants more; a bedroom wants less.
Colour temperature does as much work as brightness:
- 2700–3000K warm white — lounges, bedrooms, anywhere you relax
- 4000K cool white — kitchens, bathrooms, utility, garages
Don't mix temperatures in one sightline. Two ceilings 1000K apart in an open-plan room read as a fault, not a design choice. Our warm white vs cool white guide settles which to pick.
5. Bathrooms and IP rating
Bathrooms are zoned, and the zone decides the minimum IP rating of anything you put in the ceiling. Directly above a bath or shower is the most demanding position.
An IP20 downlight is an indoor, dry-location fitting — the majority of the range, and wrong above a shower. Get the zones right before you choose a fitting: our bathroom lighting zones guide covers what fits where.
6. Where DIY stops
Swapping a like-for-like downlight on an existing, correctly-isolated circuit is a competent DIY job. Isolate at the consumer unit and prove dead — a lighting circuit has a permanently live conductor at the ceiling rose, and downlights are no different.
Installing a new set of downlights is a circuit alteration: it needs testing and certifying, and in a room containing a bath or shower it's a special location under Part P in England and Wales. Cutting the holes is the easy part; the certification is the part that matters.
LED downlight quick-reference
| Room | Spacing (2.4m ceiling) | Colour | Fire-rated? |
|---|---|---|---|
| Kitchen | ~1.2m, over worktop edge | 4000K | Yes, if rooms above |
| Lounge | ~1.2m | 2700–3000K | Yes, if rooms above |
| Bedroom | ~1.2m, fewer | 2700–3000K | Yes, if rooms above |
| Bathroom | ~1.2m | 4000K | Yes + IP to zone |
| Top-floor ceiling | ~1.2m | To suit | Check — loft above, not a room |
Expert Help in the West Midlands
We've been on Villa Road in Handsworth since 1975, and the counter is open to installers and homeowners alike.
Bring the room dimensions, the ceiling height and what's above the ceiling. Those three facts give you the count, the spacing and whether fire-rated is mandatory — and we'd far rather work that out with you than sell you twelve fittings for a six-fitting room.
Browse the range in Spotlights & Downlights.
Frequently asked questions
How many LED downlights do I need in a room?
Space them at roughly half your ceiling height apart and keep the outer row 600–750mm off the walls. On a standard 2.4m ceiling that's about 1.2m spacing. Count from the spacing, not from a brightness target — overlighting is the commonest error.
Do downlights have to be fire-rated?
Where the ceiling separates floors, the fire resistance you cut through has to be restored — either with a fire-rated fitting or with a fire hood over a standard one. A top-floor ceiling with only a loft above is a different case; check what's above before deciding.
How far apart should downlights be from the wall?
Around 600–750mm. Closer and you get bright scalloping up the wall; further and the edges of the room fall dark, which makes the whole space feel smaller.