Domestic and non-domestic energy performance certificates review: supplementary notes

1. Introduction

As part of the review of EPCs in Scotland, additional analysis was carried out as part of the research project into the methodology, calculations, and conventions underpinning the SAP and RdSAP methodologies.

This additional analysis was concerned specifically with six different topic areas identified through the main research programme:

• RdSAP and U-values
• Thermal Mass
• Rooms in the Roof
• Community heating
• Ventilation Sensitivity: draught lobbies, flues and extract fans
• Measuring Window Areas in RdSAP

The methods used in the additional analysis varied:

• in some instances, it was to carry out a more detailed technical analysis of a specific issue;
• in some instances, it was to compare directly the differences between an RdSAP assessment of a dwelling and a full SAP assessment of a dwelling, and examining the impact of the two different approaches; and,
• in some instances, it was to highlight confusion in the conventions and to seek clarity.

The additional analysis uses several case studies, and presents information not previously available publicly. However, the overall purpose of the additional analysis was to explore how the results from the RdSAP and EPC process could be improved.

The results of this additional analysis were used to inform the presentations at the four workshops that were help as part of the research programme for this project, and were openly discussed within the workshops. The results also informed the identification and impact assessment of various recommendations published in the main report.

The information within these supplementary topic notes was deemed too technical to include in the main report on the review of EPCs, but important and appropriate enough to publish as an addendum to the main report.