Date lodged: 30 November 2017
To ask the Scottish Government what its position is on whether EPC measures for the U-value of stone construction in Scotland fairly represent actual in situ performance.
Answered by: Kevin Stewart 12 December 2017
EPCs are produced using the UK Government National Calculation Methodology (NCM) that conforms to the requirements of the Energy Performance of Buildings Directive (2010/31/EU).
Within the NCM, default U-values for the performance of building elements are provided for use in the calculation methodology where it is impractical to obtain building-specific U-values. These U-values are developed by the UK Government to be representative of typical constructions.
A recent UK Government review of the NCM resulted in changes to default values cited for solid and cavity brick construction. We are currently investigating whether a similar review of U-values for stone external wall construction is merited.