Standard Assessment Procedure SAP 2012

SAP methodology and approved software:

SAP 2012 document (October 2013, updated June 2014, with minor corrections December 2014)

RdSAP 2012 v9.93 (SUPERSEDED – used from 19th November 2017)

RdSAP 2012 v9.94 (CURRENT – used from 22nd September 2019)

RdSAP Conventions 11.4 (from 01 July 2024)

Current list of approved SAP 2012 software (15th June 2020)

Current list of approved RdSAP 2012 software (20th September 2019)

Current list of approved ECO software using RdSAP 2012 (20th August 2015)

SAP2012 Prices used by SAP and RdSAP for calculation of fuel costs.

Frequently Asked Questions

Q1. We recently installed new electric radiators in a property, having been told these were highly efficient. However, when it came to having the property assessed for the EPC a poor rating was given. Why is this?

A1. The EPC rating is based on the running costs for the dwelling calculated using SAP. Electricity is a relatively expensive fuel (around 3 to 4 times the price of mains gas), so even though all direct electric heaters are 100% efficient, the use of electric heating usually results in poor ratings. However, electric storage heaters can make use of cheaper electricity available at nighttime, so usually result in a better EPC rating than direct electric heaters.

Q2. When is the Product Characteristics Database updated?

A2. The PCDB is updated overnight on the last day of each month, so any new products added will be available in assessments from the start of the new month.

Q3. Can you tell me when a particular product will be added to the Product Characteristics Database?

A3. We can only discuss progress with PCDB applications with the manufacturer/applicant since this is potentially commercially sensitive information.

Q4. Why can’t I select an infra-red heater in SAP software?

A4. There is currently insufficient evidence of the performance of infra-red heaters to justify modelling them differently from other direct electric heaters, so they are treated as having the same performance.

We’ll add more FAQs to this page in future. If you have a question not answered above, please email SAP-help@bre.co.uk.

There are some further FAQs about EPCs on the Ministry of Housing, Communities and Local Government’s EPC FAQs page.

Green Deal Occupancy Assessments (based on SAP 2012)

The document below is the technical specification for Green Deal Occupancy Assessments and Improvement Packages which applies from 8 December 2014.

Download:

Occupancy Assessment (version March 2014) (with minor corrections December 2014)

Download the current list of approved Green Deal OA software (list dated 19 November 2017)

Download the current list of approved Green Deal IP software (list dated 19 June 2015)

 

Other SAP technical documents

These papers relate mainly to the previous consultation on SAP 2009. They can be downloaded in PDF format.

Boilers:

• STP09/B01 Changes to the treatment of boilers (gas and oil) in SAP 2009

• STP09/B02 Energy Balance Validation: Investigation of the residual energy of thermal efficiency tests on gas and oil boilers

• STP09/B03 Revision to the SEDBUK procedure for oil boilers

• STP09/B04 Analysis of results from energy performance tests on combi boilers 2008

• STP09/B05 A meta-analysis of boiler test efficiencies to compare independent and manufacturers’ results

• STP09/B06 Boiler efficiency for community heating in SAP

• STP09/B07 Efficiency tests of water heating by regular and combi boilers 2009

• STP10/B08 Laboratory tests on gas and oil boilers 2010

Domestic hot water:

• STP09/DHW01 Analysis of the EST’s domestic hot water trials and their implications for amendments to BREDEM and SAP

Auxillary energy use and internal gains

• STP09/AUX01 Review of auxiliary energy use and the internal heat gains assumptions in SAP

Occupancy and floor area:

• STP09/NOFA01 A review of the relationship between floor area and occupancy in SAP

SAP 2012 technical papers

These papers can be downloaded in PDF format.

CO₂ emission factors:

• STP11/CO204 Proposed Carbon Emission and Primary Energy Factors for SAP 2012

 

Boilers:

• STP11/B09 Treatment of Heating and Hot Water Boiler Systems

 

Heat pumps:

• STP11/HP-01 Default Values for Seasonal Performance Factor of Heat Pumps

 

Primary loss: STP11/DHW02 Primary Pipework Loss   Climate: STP11/SR01 Solar Radiation (revised version June 2014) STP11/WD01 Wind Data   Scotland Building Regulations Section 7: Sustainability The spreadsheet below is used for assessing the aspect of energy for water heating within the higher levels (silver and gold) of the Scottish building standard 7.1 Section 7 calculator for SAP 2012.xlsx (V1.0, 13/12/2017)