RdSAP 10 is the next iteration of the methodology which is currently used to calculate energy performance in existing homes. The step from RdSAP 9.94 to RdSAP 10 will introduce several significant enhancements, designed to improve the quality and scope of Energy Performance Certificates (EPCs), which are vital for home sales and rentals, as well as funding mechanisms.

While progress has been slow as a result of the approval process, Elmhurst is pleased to announce a significant development in our ongoing work with the BRE to replicate the RdSAP 10 calculation engine. After rigorous testing and collaboration, we are delighted to confirm that our calculation engine now matches all the required test cases for the various regions. This marks an important milestone in the journey towards the full implementation of RdSAP 10.

Despite this achievement, other industry providers have not yet reached the same stage. Regular meetings are being held with the BRE, the government, and accreditation schemes to ensure progress is maintained. This cooperative effort is crucial for the successful and timely release of RdSAP 10, which we anticipate could be as early as June. However, this timeline remains dependent on other scheme providers matching the required test cases and completing the necessary steps for software interface approvals.

Why is an Update to the RdSAP Methodology Important?

The introduction of RdSAP 10 is a pivotal step in the UK’s efforts to modernise its housing stock and reduce energy consumption. As the government tightens regulations and incentives around energy efficiency, accurate energy assessments are becoming increasingly important. They not only influence property values but also impact homeowners’ and landlords’ responsibilities to achieve certain energy ratings.

The updated methodology will better reflect the current state of the market and the technological advances in home energy systems.

Notable changes coming to RdSAP 10

New Technologies
RdSAP 10 will include technologies like battery storage, PV diverters, and small-scale hydro, reflecting their increasing use in UK homes and providing a more accurate view of a property’s energy efficiency.

Data Collection Changes
The new version will improve data collection by measuring all windows, offering more detailed criteria for roof rooms, and adding more ventilation options to give a clearer picture of a home’s energy features.

Improved Recommendations
RdSAP 10 will offer clearer recommendations for energy improvements. For example, heat pumps will be recommended more often for well-insulated homes, not just for those with electric storage heaters.

Carbon Impact
The inclusion of new technologies like battery storage will improve the EPC’s assessment of carbon emissions, which wasn’t possible in the previous version. This will have a significant effect on both the energy and environmental ratings.

Elmhurst Energy’s Managing Director, Stuart Fairlie comments:

“Elmhurst has been working closely with the government and BRE on the RdSAP 10 update, which will be the biggest change to RdSAP since 2012. This update, featuring the inclusion of carbon-busting technologies and other energy-related features, will provide a more accurate reflection of the energy efficiency of our homes. It’s a positive step for energy assessment, supporting the government’s goals to reduce emissions and eradicate fuel poverty.

In the meantime, we continue to lobby key stakeholders—such as estate agents, housing associations, local authorities, lenders, and the media—to ensure the value of EPCs both now and under RdSAP 10 is fully recognised. With energy assessors spending more time on-site gathering detailed property information, the accuracy of EPCs will improve, increasing their overall value. Elmhurst is advocating for recognition of the added value from more precise data collection and assessment, urging those who commission EPCs to appreciate the long-term benefits of these improvements and, as a result, pay more for them.”