Introduction
Why RDSAP 10 Matters to You Energy Performance Certificates (EPCs) play a crucial role in buying, selling, and letting residential property. With the release of RDSAP 10 in June 2025, estate agents and homeowners need to understand the impact this update will have. It marks the biggest change in EPC methodology since 2012, making assessments more accurate, inclusive of modern technologies, and in line with the UK's net-zero targets.
What Is RDSAP and Why Is It Being Updated?
RDSAP, or the Reduced Data Standard Assessment Procedure, is the method Domestic Energy Assessors use to evaluate existing homes. The move to version 10 enhances the detail and accuracy of these assessments, aligning more closely with current building practices and energy technologies, while helping support national goals such as reducing carbon emissions and eradicating fuel poverty.
Key Changes in RDSAP 10 That Will Affect Your EPC
RDSAP 10 introduces a wide range of changes that homeowners and estate agents should be aware of:
More accurate categorisation of wall types, windows, and roof rooms
Inclusion of technologies like battery storage and PV diverters
New ventilation and lighting data inputs
Air pressure testing and specific hot water tank measurements
New Data Collection Standards for Domestic Energy Assessors
Assessors will now collect far more detailed information than before, including:
Individual measurements for every window
Orientation, glazing gaps, draught-proofing, and window frame material
Expanded ventilation categories including extract fans and passive vents While this means a longer visit to the property, turnaround time for the final EPC report remains at 24 hours.
A Closer Look at Room-in-Roof Classifications
RDSAP 10 now recognises two types of room-in-roof (RiR):
Type 1: Fully within the roof space, with stud walls and no external wall visible
Type 2: Retains a common external wall, with at least 50% of it below 1.8m in height This change increases accuracy, especially in older or converted homes where roof room configurations vary widely.
Improved Wall and Insulation Assessments
Wall insulation measurements are now more precise, with options to input values in 25mm increments. DEAs can also identify up to two alternative wall types for complex property layouts particularly helpful for flats and extensions.
Recognising Modern Features and Technology
For the first time, EPCs will reflect renewable and smart energy tech like:
Battery storage systems
PV diverters (solar energy redirectors)
Small-scale hydroelectric systems Homes that have invested in these technologies will now benefit from improved energy ratings and better marketability.
Assessors can now enter air tightness test results and exact cylinder capacities. These inputs provide more realistic insights into a home’s heat retention and hot water efficiency helping homeowners make informed upgrade decisions.
Impact on Property Marketing and Value
A more accurate EPC is a powerful tool in property marketing. Buyers are increasingly aware of energy costs and sustainability, and a strong EPC rating can improve perceived value and buyer confidence. For estate agents, it’s a key differentiator.
What Estate Agents Need to Prepare For
With longer on-site assessment times, we recommend agents coordinate access efficiently. Informing sellers of the enhanced inspection process is key. However, Click’s EPC turnaround time remains 24 hours post-assessment.
Benefits for Homeowners
Homeowners will receive more relevant, tailored energy-saving advice on their EPC. The clearer recommendations like when to consider heat pumps make it easier to invest smartly and prepare for future regulation shifts.
Supporting Government Goals RDSAP 10 supports national initiatives to reduce emissions, combat fuel poverty, and transition to net zero. These updates align EPCs more closely with real-world home performance and policy needs.
The Click Approach – How Our Assessors Are Getting Ready
All Click assessors have received advanced training and software updates to comply with RDSAP 10. We’re already piloting assessments under the new standards to streamline the process for our clients when the changes go live in June 2025.
FAQs from Our Clients
Will EPCs cost more? Yes, due to the more detailed data collection involved. For pricing updates, contact Michael@clickmediagroup.co.uk
Will the assessment visit take longer? Yes, due to the additional measurements and categories. However, the final EPC report will still be delivered within 24 hours.
How do I prepare my property? Ensure full access to all rooms, lofts, and relevant documentation (e.g., cylinder specifications or air test reports).
Conclusion
A Better EPC for a Greener Future RDSAP 10 is a milestone in energy assessment for UK homes. For estate agents, it offers a sharper marketing tool. For homeowners, it provides clarity and guidance. And for all of us, it supports a greener, smarter housing sector.
