Reduced Data SAP from 1 April 2012

RdSAP has been revised so as to include additional collected data and additional recommendations for improvement. It is known as RdSAP 2009 version 9.91 and applies to all EPCs produced from 1 April 2012 in England, Wales and Northern Ireland, and from 1 October 2012 in Scotland. The revised EPCs support Green Deal, introduced in England, Wales and Scotland in October 2012.

RdSAP 9.91 improved the energy assessment of dwellings and provides better information on benefits from improving the energy performance of a dwelling. This was done as part of the continuing improvements of the methodology for energy assessments and to support the delivery of Green Deal policy. More information on the Green Deal is available on the DECC website


RdSAP 9.91 Summary of changes

RdSAP 9.91 Appendix S (RdSAP specification)

RdSAP 9.91 Appendix T (improvement measures)

RdSAP conventions

The current RdSAP conventions (updated December 2012) can be downloaded here.