GU10 LED Building Regulations

Is this the end for GU10 LED lamps? Let’s hope so…

The 2026 edition of Approved Document L, Volume 1 has now been published and there’s an interesting change for lighting.

For new and existing dwellings, internal luminaires should have light sources achieving a minimum luminous efficacy of 105 light-source lumens per circuit-watt, subject to the provisions for specialist light sources.

So, what could this mean for the humble GU10 LED lamp?

Many GU10 LED lamps currently on the market fall well short of 105 lm/W. Could this finally encourage a move away from the cheap, replaceable GU10 lamp and towards better-designed, more efficient lighting solutions?

Those who know me will know that I’ve never been a great fan of GU10 LED lamps. There have been plenty of debates with fellow lighting enthusiasts over the years who have a very different view!

But don’t just take our word for it.

We’ve created a simple lm/W calculator on the Circalume website. Enter the wattage of a product and the manufacturer’s stated lumen output and it will calculate the efficacy for you, Pass or Fail against the 105 lm/W benchmark.

Sometimes the numbers tell the story better than we can.

And for anyone looking for a little nighttime reading, or perhaps a cure for insomnia, the full Approved Document L 2026 is available on GOV.UK.

So, is this the beginning of the end for the GU10 LED lamp?

Let’s hope so…

For more night time reading, or if you have insomnia, here's a link to the publication: https://www.gov.uk/government/publications/approved-document-l-2026