The EPR Conventions Working Group, comprising TrustMark, Ofgem, Retrofit Assessment Scheme Providers (ECMK, Elmhurst, Quidos, Sterling), and wider industry stakeholders has updated the Energy Performance Report (EPR) Variation Convention to reflect the transition from RdSAP 9.92 to RdSAP 10.
These changes will apply to new projects with Retrofit Assessments conducted on or after 10th November 2025.
Key updates include revised requirements for the pre- and post-installation recording of ventilation, aligned with the latest ECO4 and GBIS regulations. These changes are designed to ensure consistency, compliance, and improved quality across retrofit assessments.
We strongly encourage all assessors to familiarise themselves with the updated conventions to ensure readiness ahead of the implementation date.
Ventilation Upgrades
Where ventilation in a property has been upgraded as a part of the project, then the updated ventilation system must be reflected in the post EPR, even though Ventilation is not an ECO4/GBIS eligible measure.
Air Tightness Testing
All airtightness testing must be conducted by an appropriately trained Level 1 or Level 2 airtightness tester who is registered with a government-approved Competent Person’s Scheme.
The testing itself must be carried out using calibrated equipment in accordance with CIBSE TM23. The building preparation and testing procedure to be used is also detailed in CIBSE TM23.
For an airtightness test to be valid and used within an RdSAP lodgement, it must be lodged to the registered Competent Person’s Scheme, with the resultant certificate provided as documentary evidence for audit purposes.
