Tuesday I was at the living green center at Morden Hall park to discuss Green Deal and the potential car crash that is energy efficiency investment on traditional buildings. James Lloyd had organised a superb meeting of the interested, impacted, insightful and people with expertise in energy performance of the traditionally built houses of the UK (solid wall buildings built before 1920 or to put it another way 25% of the total UK housing stock or 33% of the Welsh housing stock)
The main issue which came out early on in the meeting is the flawed data being used and applied on old buildings through the Standard Assessment Process (SAP) or actually Reduced Data SAP (RDSAP) to calculate heat loss from the various bits of a building. This estimated heat loss is then used to calculate savings which in turn in the Green Deal process is the business case for the house holders decisions to agree to the investment on certain measures (e.g. solid wall insulation) The payback for these measures will be added to the electricity bill of the house holder and must keep within the ‘golden rule’ i.e. the total of the green deal payback and utility bill will be less than your current bill. But if the data in SAP which after all was developed for new build is 30 to 40% out on traditional built fabric then we have a problem. Namely the measures wont pay for themselves and the house holder could be worse off. But Green Deal is a superb idea it just needs better foundations to make sure we all get the expected savings in energy, cash and carbon
Then we got on to the challenge of the traditional build and what is an appropriate measure, Green Deal assessors competency of dealing with older buildings, moisture management, whole building performance, aesthetic impact and so on. But that is a whole other blog. It was a good day and more will be coming out on this…but in a solution sort of way . After all we all want it to work!