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Proposed changes to the Standard Assessment Procedure (SAP)

The Standard Assessment Procedure (SAP) is a methodology used to assess the energy performance of homes and thereby helps deliver many of Government’s energy and environmental policy objectives.

Objectives of the consultation

The SAP assessment is used for many purposes – including compliance with Building Regulations, and to produce Energy Performance Certificates. This consultation set out the following areas of the methodology which are under review and sought views on proposed changes:

Amendment 1 – Carbon Dioxide Emission Factors
Amendment 2 – SAP Heating Regime
Amendment 3 – Distribution Loss Factors for Heat Networks
Amendment 4 – Lighting calculation
Amendment 5 – Thermal bridging
Amendment 6 – Areas next to unheated spaces
Amendment 7 – U-values to walls in existing dwellings
Amendment 8 – Hot water methodology
Amendment 9 – Summer temperatures assessment
Amendment 10 – Mechanical Ventilation systems
Amendment 11 – Chimneys
Amendment 12 – Storage heating – secondary fraction
Amendment 13 – Solid fuel heating efficiencies
Amendment 14 – Solar PV - overshading
Amendment 15 – Solar PV - diverters
Amendment 16 – Product Characteristics Database – boilers
Amendment 17 – Heat pump default values
Amendment 18 – Technology costs
Amendment 19 – Heating Controls

This consultation concluded on 27 January 2017.

Supporting papers

To download the consultation document, please follow the link below.

  • Proposed changes to SAP - Consultation document

In addition to the consultation document, draft specifications for the new versions of SAP was made available on the BRE website. A version of SAP software just for the purposes of this consultation (cSAP) was also prepared with the recommended approaches built into it. This could be found on the ISAP website.

CIBSE response

The Homes for the Future Group, chaired by Ashley Bateson of Hoare Lea led on the response to this consultation. A special workshop was convened with specific input from Stephen Lloyd (Hoare Lea), Barny Evans (WSP), Emily Nolan (Arup), Ross Boulton (Buro Happold) and Jon Gregg (Buro Happold). The CHP & District Heating Group also consulted members and contributed through Group Chair Phil Jones and Secretary Minhajuddin Mohammed (Engie).

A general need was highlighted to ensure improved compliance, more rigorous enforcement of Building Regulations and for greater diligence in the building control industry to drive higher quality residential development. At the same time as rigour is increased, however, it does imply that competency in the assessment and checking process needs to increase. We recommended that mechanisms to check the competency of assessors, the SAP certification bodies and building control officers are reinforced. This may require additional monitoring in order to limit performance gaps that can arise from the Part L assessment and construction activities on site.

Specific areas of the consultation which were considered in detail included the amendment of distribution loss factors for heat networks, and proposals to change the assessment of internal temperatures in summer. CIBSE Research Manager, Anastasia Mylona also contributed her expertise on the latter issue. Some work was undertaken to discuss the consultation with other organisations such as BESA and the Solar Trade Association with the aim of being able to reinforce messages that we all agreed on.

To read the full CIBSE response please follow the link below.

Results of the consultation and next steps

The Government published the outcome report of the consultation on proposed changes to the Standard Assessment Procedure (SAP) on 17 November 2017. The document sets out the Governmet response to the feedback received, to be reflected in the updated version of the methodology, SAP 10.

To read the Government report, please follow the link below.

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