The Energy Performance Certificate (EPC) regime is undergoing a significant update with the introduction of the Reduced Data Standard Assessment Procedure (RdSAP) 10. This new version, implemented last month (June 2025), marks the most substantial revision in over a decade to the methodology used for assessing the energy performance of existing residential properties.
RdSAP is the simplified methodology used to produce EPCs for existing dwellings. The latest version introduces new data inputs, revised assumptions, and structural changes, all aimed at improving the accuracy of assessments. The goal is to ensure EPCs more closely reflect how homes are actually used, enabling more informed decisions around energy efficiency.
For landlords, this development means increased responsibility. EPCs are already a legal requirement for letting residential properties, with current minimum standards set at EPC rating E in England and Wales. An inaccurate rating can prevent a tenancy from proceeding. The government has proposed increasing the minimum requirement to EPC rating C for new tenancies from 2028 and for all tenancies from 2030.
This shift places a greater onus on landlords to maintain accurate records of any energy efficiency improvements. In particular, evidence of insulation works, heating system upgrades, and installation of double glazing will be essential. Without supporting documentation, properties may receive lower EPC ratings than warranted, potentially triggering costly and unnecessary retrofit works.
For tenants, the changes offer increased transparency. More accurate EPCs will allow tenants to compare properties with greater confidence, particularly in relation to potential energy bills. For homeowners looking to sell, a robust EPC that properly reflects energy efficiency improvements may enhance the property’s appeal.
The challenge, particularly for landlords, will be balancing the potentially significant costs of upgrading properties to meet higher EPC standards against the benefits of improved marketability and regulatory compliance. As EPCs become more data-driven and evidence-dependent, the importance of good record-keeping cannot be overstated.
For more information or assistance, please contact Arjun Mediratta in our Dispute Resolution team at Rooks Rider Solicitors.
