Lighting advice from the showroom

In short. Cosmo Lighting Kensington's guides answer the questions the showroom counter hears every week, and say plainly which jobs are a licensed electrician's.

• Warm white vs cool white: The Kelvin number on the box decides whether a room feels like a lounge or a dental surgery. Here is how to read it.
• LED downlight flickering: Nine times out of ten it is the dimmer, not the downlight. The rest is loose wiring, a dying driver or a globe that was never dimmable.
• How to change a downlight: Globes and plug-in units are a two-minute job. Anything with a terminal block is a licensed electrician's.
• Ceiling fan wobble and noise: A wobble is almost never the motor. It is a blade a few grams heavier than its neighbours, a loose screw, or a bracket that was never tight.
• How many downlights per room: Count by lumens, not by watts, and space them by the ceiling height. A living room rarely needs the grid of twelve a builder draws.
• Halogen to LED downlights: Most halogen downlights take a GU10 or an MR16 globe. Which one you have decides whether it is a two-minute swap or a job for an electrician.
• Pendant lights for a kitchen island: Two or three pendants, hung so you can see across the bench and spaced so the light falls evenly along it.