Lighting is now assessed bulb by bulb rather than by fitting. Assessors count and classify every bulb in the property, LED, CFL, or incandescent, rather than estimating from fitting types.

This lets the EPC model reflect actual lighting energy use more accurately: the more low-energy bulbs you have relative to the total, the better your lighting score. Properties with a lot of halogen or incandescent bulbs may see a slightly lower score than under the old methodology.

The change reflects how widely LEDs have been adopted in UK homes, while still accounting for any inefficient bulbs that remain, giving a more realistic picture of a property’s actual energy use.