SAP calculations for a loft dormer conversion, insulation has already been installed 150mm celotex on 50% of the roof and 100mm celotex on the other 50% The sap calculations have to be compliant with current British building regulations.
Budget: £250 – £750 GBP
Sap calculations for a loft dormer conversion proving that the insulation I have installed is compliant with current British building regulations