10 May 2010

Part L 2010 Lighting changes

The technical details on Part L are now with us and I am slowly getting my head around them. One of the things that stands out is that we now need to refer to supplementary documents and, in particular, to one called the Domestic Building Services Compliance Guide.

Buried away on p 123 of this document is the guidance on lighting, and lo and behold, it’s changed significantly from the guidance in Part L 2006.

What did Part L 2006 call for?
• for 1 in 4 light fittings to be low energy, or for 1 every 25m2
• for all these fittings to be dedicated fittings (no bulb switchovers later on, matey)
• 40 lumens per circuit-watt or better as the definition of low-energy. Almost all fluorescents and some LEDs will meet this.

How does Part L 2010 differ?
• it asks for 3 in every 4 outlets to be low energy
• but it relaxes the requirement for the fittings to be dedicated, meaning that people will be free to switch over to any old bulb after the building is finalled
• the new efficiency threshold is increased to 45 lumens per circuit-watt.

What it means in effect is that it will be extremely difficult to floodlight rooms with halogen downlighters, but much easier for people to ditch all the energy saving bulbs which remain hugely unpopular with consumers. In effect, all the developer has to do is to design a traditional lighting scheme with no dedicated fittings at all, and just put energy saving bulbs in everywhere. Or, for the really skin-flint developer, no bulbs at all.


  1. Dave HoworthMay 10, 2010

    Yes, it looks a lot easier to fudge now.

    The exclusion of lights less than 5 watts also appears to mean that you can't count a ceiling full of individual LEDs towards your low-energy lighting!

    So one step forwards, two steps back.

    Perhaps if we continue to have no decision on a government, it will slow down this kind of nonsense.

  2. Well they really had to let go of 'dedicated fittings only' because it was unworkable. Common practice is for the sparky to return after sign off and replace dedicated fittings with ordinary ones. Even if the occupier is happy using CF bulbs, there is more choice at lower prices with ordinary bayonette fitting units.

    So, the future's bright, the future's flurescent! Perhaps we should have those nice flurescent units they have in suspended ceilings. Yes, our houses might look like institutions and might have more lights than they do now but hey, it's 'low energy'.

    I don't suppose there is any chance that the powers be might acknowlege that this is a waste of time and that the amount of power used in lighting is overwhelmingly dependent on the USERS of the house. Attempting to regulate fixtures like this is pointless; apart from having no control over the number of lights turned on, it is quite usual to have many table, standard or work lights in a house that are not fixed and so not open to being regulated at all. It's all really tiresome.

  3. Dave, your conclusion about LEDs isn't right, according to my reading of the guide.

    LED fittings are totally excluded from the count of light fittings. Consequently if you have LED fittings (of 5W or less) in every room, and no other fittings in the house, then you are fully compliant.
    And, unless you install tens of LEDs per room, this is likely to be a good low-carbon solution too, AND one which (with good quality fittings) is likely to be very acceptable to consumers too.

    Of course the option Mark mentions - designing a traditional lighting scheme with no dedicated fittings at all, with standard CFLs everywhere - would be regrettable, although likely to happen.