A major update to the Energy Performance Certificate (EPC) system is set to take effect in just over two weeks, marking the most significant changes in more than a decade.This overhaul is based on the updated Reduced Data Standard Assessment Procedure (RdSAP),the method used to assess a property's energy efficiency using a combination of measured data and assumptions about building construction and usage.

 

What's Changing?

The new methodology will allow for:

• More accurate assessments, particularly for flats and mid-terrace homes
• Improved reflection of real-world energy use
• Greater reliance on specific, documented property features
• Assessors will now gather more detailed information, including:
• Glazing types and condition
• Verified heating system details using model numbers or manufacturer specs
• Presence of smart heating controls

 

Crucially, only documented upgrades, like added insulation or window replacements will positively influence a property's EPC score. If evidence cannot be provided, the property could be rated less efficient than it actually is.

 

Why It Matters

Previously, when key details (like heating system specs) weren't available, default assumptions were used, often underestimating efficiency. The new system reverses this by penalising lack of documentation, which could cause EPC ratings to drop unless clear records are provided.

 

Better for Flats and Terraced Homes

RdSAP now uses more accurate methods for calculating heat loss and insulation, which is especially beneficial for property types that were previously disadvantaged by broad assumptions. Many owners of flats and mid-terrace houses may see their EPC scores improve as a result.What Agents and Landlords Should DoIndustry body Propertymark emphasises that this is a critical time for agents to support landlords. With EPC scores now depending more on what can be proven, keeping receipts, certificates, and detailed records of energy efficiency improvements is essential.Without these, even recently upgraded homes may be downgraded in EPC ratings, potentially leading to unnecessary costs for additional upgrades. Propertymark is also calling for Clear government guidance, Realistic timelines for implementation and Financial support for small landlords.These points align with broader calls for EPC reform and fairer access to funding for energy improvements.