Low Energy Lighting (LEL)

At the time of writing the methodology for EPC assessments of existing dwellings is RDSAP 9.94. The much anticipated RDSAP 10 update has not happened yet and a significant methodology overhaul from RDSAP to the Hone Energy Model (HEM) is proposed for 2025.

Essentially, for your EPC, the goal is to have all of your light fittings populated with 'Low Energy Lighting' (LEL). We'll define what LEL is here, and how lighting is assessed.

For the EPC assessment, we count the number of lights in the property, and we count the number of those which are classed as 'Low Energy Lighting'.

Currently we count the number of light fittings rather than bulbs, so a chandallier would be counted as 1. Also, where 4 or more spot lights are in the same room, we count half the number of lights - so 6 spotlights would be counted as 3. When the assessment methodology for existing dwellings is updated from version 994 to version 10 however, every individual bulb will be counted.

We only count light fittings inside the property. We don't count light fittings on the outside of the property or in areas that we don't consider for the EPC assessment - such as unheated garages or conservatories where they are separated from the main building by an external quality door. We do however include fixed lighting under kitchen wall cabinets and plinth lights etc.

Note, that the assessment procedure considers Low Energy Lighting to include:

• LED lights
• Fluorescent tubes (FT)
• Compact Fluorescent Lamps (CFL)

Importantly, it does not consider Halogen bulbs to be Low Energy Lighting, and of course 'traditional' filament bulbs aren't either.

Note also that empty fittings have to be considered non-LEL unless the fitting is so designed that it will only accept LEL bulbs.

When the assessment methodology for existing dwellings finally moves up from version 9.94 to version 10, the assessment procedure will change slightly and CFLs will be counted individually, separately from LEDs.

Moving up to 100% 'Low Energy Lighting', from a lower percentage, will only make a small difference to your EPC rating.

For example if we take my 3 bed terraced house (covered in our Case Study 2 page), where I have 18 light fittings, moving from 0% to 100% LEL would take me from a 66D to a 68D rating. That's an improvement of only 2 SAP points. If I had moved up from 50% to 100% it would only have improved my rating by 1 SAP point.

Those one or two SAP points however could be the ones that take you up a band from say a D to a C rating, if you were currently on the threshold, so considering the ease of effort and low cost, this is the first step that most homeowners will complete.

In summary, before calling out a Domestic Energy Assessor, just run round your property and replace any non-LEL bulbs with LEL bulbs.

Click here to return to our 'Improve Your EPC' main page, and see if there is another way you could improve your EPC rating.