13 Jun 2012

Is there anything good in the Green Deal?

Yesterday, I went to a meeting in London put on by SPAB (Society for the Protection of Ancient Buildings) called to update people about their research into energy efficiency measures used in older properties. SPAB have become remarkably active in this field recently and there were nine presentations, each on different projects.

At the very heart of this research is a central fear that adding piles of insulation into old buildings (or indeed new ones) may cause havoc with the moisture levels in the fabric and may end up causing more harm than good. All across the country, researchers are beavering away measuring temperatures, U values, airtightness, relative humidity levels, rainfall, trying to work out what happens to homes both before and after treatment. What emerged was how little we really know about the behaviour of buildings, and how little research has been done.

The establishment view is summarised by two standards, BR 443 which deals with heat loss and sits behind the SAP calculations and BS 5250 which deals with condensation risk. In theory, if your wall assembly (or roof or floor) meets BR 443 and passes the BS 5250 test, then all is hunky dory. But in real life, most of the researchers were saying that neither standard really cuts the mustard and that the moisture modelling suggested by BS5250 is so simplistic that it's a veritable danger.

Which begs the question, what should replace it? Much was made of the more complex, dynamic WUFI model, though some pointed out that not everyone agrees that WUFI is the answer. Surely the Germans would know the answer? Maybe, but Neil May made the interesting point that he had reviewed much of the German language literature and wasn't convinced that their understanding was much better than ours. It seems that moisture behaviour in wall and roof assemblies remains poorly understood and therefore unpredictable.

So what's this all got to do with the Green Deal? Actually, it's pretty central because here we have a government policy which is designed to bounce us into both internal and external wall insulation in older properties, precisely the sort of measures which SPAB are highlighting may cause future problems. The Green Deal wasn't the purpose of this meeting, which was arranged months ago, but nevertheless the Green Deal did rather dominate proceedings and several interesting things came to light. To their credit, DECC (the government department behind the Green Deal) provided two spokepoeple, Nicola O'Connor and Steven Daniels, who explained some of the logic behind the recent publications, but they shot off pretty soon after their presentation and weren't around to hear the deluge of disquiet that followed.

One issue that kept emerging was the initial survey. There are, apparently, 45 measures which might be eligible for Green Deal finance, but which of these are suitable in any given household depend on the survey assessment by a professional who, it emerged, is going to be paid the princely sum of around £30 for undertaking this work. How much time is that going to buy? 10 minutes, if you are lucky. And will the advice be any good? More likely, it will be sales advice with commission for any number of supposedly Clean Tech businesses. "Will the survey be independent?" rang out the question from the floor. "We can't insist on this, but it will be impartial," replied DECC. "Hmmm", went the audience. A good independent survey, it was pointed out, like the ones Parity Projects undertake, is more likely to cost around £300-£500. Are "ordinary people" going to be happy to fork out an amount like this for a proper survey which might tell them to do nothing?

Then there is the warranty/guarantee. Apparently, there is to be some such scheme in place for Green Deal work, but exactly how it might work is hard to fathom. 25 years was mentioned, but can any building work be guaranteed for 25 years? This seems fanciful. And the loan is to be attached to the utility bills of the house, rather than the person who negotiated it, so if the house is subsequently sold, the loan goes with it.

Can you imagine what a sales boost this will be? "Oh, by the way, you have to pay £500 a year extra on your fuel bills until 2030 for all that insulation we stuck on the bedroom walls, and that air source heat pump which is in the garage but which we don't use very much."

More to the point, can you imagine big finance houses wanting to lend money on these terms? Combine the risk of an-as-yet unknown borrower with a warranty for work undertaken by others and just what would the interest rate be? That's a key point, and one that remains to be addressed. But if it can't beat a bank loan, or peer-to-peer lender Zopa, then what's the point bothering?

All in all, not a good word was to be heard for the Green Deal. I was almost beginning to feel sorry for it by the end of the day. Almost, but not quite.


  1. I would prefer you didn't lump internal and external insulation in the same sentence "bounce us into both internal and external insulation" as they have quite different problems:
    Internal insulation is what really worries me - the potential to damage the fabric of the building through moisture accumulation from both condensation from inside moisture vapour and build up of rain penetration.
    External insulation I like, but then I'm not precious about the external appearance of buildings, I'd rather have something that works. Planners probably disagree. I would further suggest the issue is not about SPAB's listed buildings: they've lasted for ages as they are, leave them alone - listed buildings only comprise around 1-2% of the stock.
    From my viewpoint the real issue we need to resolve is planning in conservation areas for upgrading un-listed buildings with external insulation. Clarity at a local planning level would do much to enable safe, reliable insulation methods to become economic, but I suspect this will take years to become a reality as there's no "market" to fund this work.
    Nice Blog though! Yours, a Cynical Passivhaus Consultant

  2. Some interesting points here. I am one of the researchers beavering away -- in this case in Wales -- using WUFI *and* monitoring temperatures and moisture content in real walls before and after the application of external and internal insulation. We expect to have some robust results later this year.