Changing to more energy efficient lighting such as LEDs (light-emitting diodes) reduces electricity demand. Lighting controls can use sensors and timers to minimise lights being on in unoccupied areas.

If a building’s lighting is more than a decade old, replacing light fittings and controls is one of the easiest 'quick wins'. It may also be a legal requirement. Some high energy light fitting classes have been banned or are being phased out. An audit should be commissioned from a professional to ensure legal compliance and assess potential payback times for installing new lighting and controls.

New incandescent and halogen lights have been largely removed from sale in the UK and are only available for specialist applications.  LED (light-emitting diode) or CFL (compact fluorescent lamp) lights offer a vastly more efficient alternative. For commercial applications, LED prices and technology have improved so much that they are now almost always the favoured replacement choice. This includes for replacing emergency lighting, for which UK standards changed in 2016, so again make sure the building still complies.

Lighting controls can greatly reduce the energy use and carbon emissions of even the most efficient lighting systems.12 Occupancy sensors can turn lights on, and timers turn lights off automatically. Installing dimmable light fittings can cut down energy usage further.