Reduced Data SAP (RDSAP)
What is the Reduced Data SAP (RDSAP) methodology?
RDSAP is the new Government-approved standardised system for undertaking an energy survey on an existing dwelling. A full SAP (standard assessment procedure) requires many data items that cannot be seen in a survey (or take too long to collect). RDSAP is an industry-agreed standard set of data items and a standard way of inferring the missing data.
Will it be used to produce energy performance certificates in England and Wales?
RDSAP will be used as the standard methodology to produce the Energy Report as part of the Home Condition Report. Home Inspectors, who will produce the Home Condition Report, should be trained on how to assess the energy efficiency of a property using the RDSAP methodology.
The Government has recently confirmed that RDSAP will be the methodology that will be used to produce energy performance certificates in the rented sector.
Will it be used in Scotland and Northern Ireland?
The devolved administrations have yet to formally announce the methodology to be used in existing dwellings.
What is RDSAP 2001 and RDSAP 2005?
RDSAP 2001 is based on the full SAP 2001 methodology. RDSAP 2005 is based on the full SAP 2005 methodology that is due to be used in England and Wales as part of the revised Part L building regulations from 6 April 2006. (source; NHER)