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The History of SAP Calculations. How SAP Assessments Started, What Is Their Future

The origins of SAP can be traced back to the Building Research Establishment (BRE) and the former Department of the Environment. SAP was developed based on the BRE Domestic Energy Model (BREDEM) and was first published in 1993. Over the years, SAP has undergone several updates to enhance its functionality and accuracy, with significant revisions occurring in 1998, 2001, 2005, 2009, 2012, and most recently in 2022. 

Alex Papaconstantinou, founder of, one of the UK’s largest SAP agencies, says that SAP calculations are the UK government’s approved methodology for the energy assessment of new dwellings. SAP is also the backbone of the Reduced Standard Assessment Procedure (RdSAP) used to calculate the energy rating of existing dwellings.

The History of SAP Calculations

In 1994, SAP gained recognition when it was officially referenced in the Building Regulations as the primary method for evaluating the energy performance of residential properties. This acknowledgment solidified SAP’s role in assessing the energy efficiency of dwellings and its importance in promoting sustainable building practices. 

Another significant milestone for SAP came in 2007 when it was adopted as the underlying methodology for Energy Performance Certificates (EPCs). 

EPC, in the UK property market, are now used by law in order to provide information on a property’s energy efficiency and environmental impact, helping potential buyers or tenants make informed decisions. 

To simplify and streamline the assessment process for existing dwellings, Reduced Data SAP (RdSAP) was introduced in 2005. RdSAP offers a more straightforward and cost-effective approach by utilizing a predefined set of assumptions about the property, reducing the amount of data that energy assessors need to collect. Overall, the history of SAP showcases its evolution as a vital tool in evaluating the energy performance of buildings. From its inception and based on the BREDEM model to its integration into building regulations and the introduction of RdSAP, SAP has played a crucial role in promoting energy efficiency and sustainability in the construction industry.

The Future of SAP Assessments 

In response to guidance from the Climate Change Committee (CCC) and a scoping study initiated by the former Department for Business, Energy, and Industrial Strategy, the government is in the process of formulating an enhanced methodology to bolster accuracy, resilience, and alignment to achieve net zero emissions. 

A consultation was released in December 2023 regarding this innovative methodology, known as the Home Energy Model, with the deadline for feedback set for 6 March 2024, allowing stakeholders from various industries to contribute to its refinement. 

The Home Energy Model is currently in the developmental phase, with plans for its initial version to be integrated into conjunction with the Future Homes Standard by the year 2025, marking a significant step towards advancing sustainability, renewable energy, and energy efficiency in residential buildings.

How does the above affect new homeowners? 

SAP Assessments are here to stay, and any homeowner must comply with the legislation. Whether their name will remain SAP Assessments or change to something else under the Futures Homes Standard next year, they will be a significant methodology in proving the energy efficiency of new dwellings. Any person building a house will need to familiarise themselves with the requirements and ways to achieve compliance.