In the UK the current methodology the government employs to assess the energy efficiency of houses is known as the Standard Assessment Procedure (SAP). This procedure serves two primary purposes:
Firstly, it is utilised to ensure that new homes adhere to the energy efficiency standards outlined in Part L of the Building Regulations. This helps in promoting energy efficient construction practices and reducing the overall carbon footprint of buildings in an industry that is failing to keep up with a demand for energy efficiency homes.
Secondly, the SAP methodology produces Energy Performance Certificates (EPCs) for all new and existing homes. The EPC provides valuable information to prospective occupants, potential buyers, landlords, and tenants regarding the energy efficiency of a particular property, enabling them to make informed decisions about retrofit costs.
Alex Papaconstantinou, founder of epc4less, a company that provides SAP Calculations nationwide, says “owners of new homes, developers and architects should involve a SAP assessor early in the design process in order to ensure compliance As Design, rather than having to do remedial work As Build”.
How did the SAP Assessments originate?
Historically, The Building Research Establishment (BRE) developed SAP, based on the BRE Domestic Energy Model (BREDEM), and first published it in 1993. It has since been updated periodically in 1998, 2001, 2005, 2009, 2012, and most recently in 2022.
In 1994, SAP was referenced in the Building Regulations for assessing dwelling energy performance, and in 2007, it became the methodology for Energy Performance Certificates (EPCs).
Reduced data SAP (RdSAP) was introduced in 2005 as a simpler and more cost-effective method for evaluating existing dwellings, using a set of assumptions to reduce the amount of data collected by energy assessors.
The Future of SAP Assessments
For the UK, the current version of SAP is SAP 10.2. The current version of RdSAP is RdSAP 2012. The government has produced an RdSAP update (RdSAP 10), which became available for use in early 2024.
The government is currently working on enhancing the accuracy and reliability of its domestic energy rating methodology in an effort to achieve net zero emissions, based on recommendations from the Climate Change Committee (CCC) and a scoping study conducted by the former Department for Business, Energy and Industrial Strategy.
To ensure transparency and inclusivity, a consultation on the new methodology, known as the Home Energy Model, was released in December 2023. As of that time, the consultation provides an opportunity for the industry to actively engage in the ongoing development process.
It is important to note that the Home Energy Model is still in the developmental phase, and its initial version will be implemented in conjunction with the Future Homes Standard in 2025.
SAP Assessments and Owners of New Homes
“SAP Assessments have become an integral part of the UK housing industry and every homeowner must adhere to the regulations” says Alex. “Regardless of whether they retain the name SAP Assessments or undergo a rebranding as per the Futures Homes Standard in the upcoming year, these assessments will continue to play a vital role in demonstrating the energy efficiency of newly constructed homes throughout the UK”.