Spacing: the rule that prevents a runway
The most common mistake is a grid of identical downlights at 900 mm centres, which lights the floor evenly and the room not at all. A workable rule is spacing equal to roughly the mounting height above the work plane: in a flat with a 2.7 m finished ceiling, that is about 1.7–1.9 m between fittings for general light, tightening to 600–800 mm where you are washing a wall.
Light the vertical surfaces. A downlight 300–400 mm off a wall, aimed to graze it, makes the room look bigger than the same fitting in the centre of the ceiling. Count fittings against a target of 150–200 lux in a living room and 300–500 lux over a kitchen worktop — the downlight calculator does the arithmetic.
What you are buying
| Type | Typical wattage | Price per piece | Notes |
|---|---|---|---|
| Basic LED, fixed, 3" | 7 W | ₹450–750 | Passages, utility |
| Good COB, fixed, 3" | 10–12 W | ₹900–1,600 | Living and bedrooms |
| Adjustable gimbal | 12 W | ₹1,300–2,400 | Art, wall washing |
| Trimless / plaster-in | 10–15 W | ₹2,600–6,500 | Where no trim is wanted |
| Anti-glare deep baffle | 12 W | ₹1,800–3,800 | Bedrooms, reading zones |
Add ₹450–900 per point for conduit, wire, switching and cut-out. A 2BHK typically takes 34–48 points across the whole flat.
Downlight, spotlight, track light
A downlight is recessed and fixed in position. A spotlight is aimed — it may be a gimbal downlight or a surface fitting, but the defining feature is that you can point it. A track light is a spot on a powered rail, so its position as well as its aim can change later. If the artwork is not bought yet, track buys you the right to change your mind.
Two specification points decide whether the room looks good: beam angle and glare. Use 24–36° for general light and 15–24° for accent. And look for a recessed light source with a deep black baffle — a cheap fitting with the diode flush at the ceiling plane puts a bright dot in every photograph and in your peripheral vision. Check CRI and colour temperature before you buy a whole flat's worth.
Frequently asked questions
How many downlights does a 12 × 12 ft bedroom need?+
Four to six 10–12 W fittings at roughly 1.8 m centres, plus a bedside layer. Six identical lights in a rigid grid is usually two too many — better to use four for the field and put the remaining budget into a reading light and a cove.
What is the difference between COB and SMD downlights?+
COB packs the diodes into a single emitter behind a reflector, giving a controlled beam and a cleaner cut-off — better for accent and general light. SMD spreads many small diodes behind a diffuser, giving flatter, broader output. Most quality residential downlights are COB.
Can downlights be installed without a false ceiling?+
Not the recessed kind — they need 60–100 mm of void. Without a ceiling, use surface-mounted cylinders or a track. Retrofitting recessed fittings into a slab is not an option in an RCC flat.
Why do some downlights flicker on a dimmer?+
Because the driver is not dimmable or the dimmer is not rated for LED loads. Both have to be matched, and the total load usually needs to stay above the dimmer's minimum — three 10 W fittings on a 100 W dimmer will often misbehave.