In an early post called ‘are solid walls really that bad at insulating’ I wrote about the fact that some research has been done on U values of solid walled buildings and how they were different from those calculated in BuildDesk (this is one of the main software programmes that are used for calculating U values in the UK and hence forms the basis for calculating amounts of insulation etc). Well I have decided to create a link to the report called the SPAB Report by Dr Caroline Rye. This is a pdf of about 1.2Mb.
Effectively is says that:
1. Nearly 80% of the BuildDesk U value calcs were significantly wrong compared to the in-situ tests (i.e. what happens in real life)
2. The BuildDesk calculations were worse at the older stone walled buildings, but OK with the more modern walls they tested
3. In virtually all cases the Build Besk calculations showed higher U values than were actually measured and hence it underestimates the thermal performance of the wall
4. The thicker the wall the better the thermal performance
5. The need for modern radical insulation measures is often not necessary and could have harmful consequences
So again if you are looking at a Barn Conversion you may wish to use this report and the figures it contains to show your architect / building control. This is a really vital area of work that is so important to get right, otherwise we risk creating no end of problems for our heritage in the future, as well as using un-necessary resources in the meantime. Please share this report as widely as you can.