29 Jul 2007

Insulation sales up just 5%

Picked up this intriguing snippet from someone who works for Sheffield Insulation, our largest supplier of insulation for the construction industry. He said that insulation sales were up by about 5% as a result of the changes brought about in 2006 by Part L revision. In theory, they should have increased by a lot more.

Also on a similar theme, a prominent boiler manufacturer tells me that sales of non-condensing boilers, which should have been kicked into touch for all time by Part L changes, are in fact holding up well. Many installers are still quite happy to fit whatever the householder wants. As far as the replacement boiler market is concerned, Part L compliance is optional, as there is no way of enforcing it.


  1. Mark

    I calculated 18 months ago that a new semi-detached house could meet the 2006 Regs. by using roughly 8% more insulation. So it seems this rough estimate has been borne out.

    The rest of the improvement could, it seemed then, be provided by a condensing boiler, 15 mm more hot water tank insulation (yes, 15 mm) and some minor items which I can't remember.


  2. Mark,

    This is a good point you have made.

    With regards to insulation recommended on new dwellings in the future, I suggest you read the following document recently released by CLG (if you have not already viewed):-

    Building Regulations: Energy efficiency requirements for new dwellings - A forward look at what standards may be in 2010 and 2013

    Located at:


    The document is free to download at the bottom of the page.

    Look at "Table 2: Compliance package for 2010 for 100m2 gas heated detached house"

    Regulations for roof insulation between joists is 250mm thick at the moment, whereas 2010 would need to be between 450-500mm thick!

    Other main points suggested are:-

    Wall u-value of 0.22W/m2K,
    Window u-value of 0.9W/m2K (eg triple glazing with argon),
    Mechanical extract ventilation,
    Air permeability of 3m3/hour/m2 or less (currently 10m3/hour/m2),
    70% of light fittings to be low energy.

    Would like to see your thoughts on this?



  3. David,

    Thanks for your comments. Very helpful, as usual.


    I hadn't seen that document - but I have now. V interesting read. Although there is in fact nothing surprising there: 2010 is PassiveHouse lite, 2013 is PassiveHouse full stop.

    My first thought is what will happen to Part L as applied to the existing stock. It hardly makes sense to build an extension with such low U values, if the rest of the house remains as is.

    I also worry about reliance on MVHR. I still don't think it's been proven to be effective in the UK climate. But this is nitpicking. Broadly, I see no reason why we shouldn't move this way for new builds. There may be some lessons to be learned along the way but, without trying, how are we going to learn them? It remains an incredibly bold experiment to roll out such low energy housing across the entire country. No one has tried that before.