NATIONAL RETROFIT HUB’S RESPONSE TO THE HOME ENERGY MODEL: ENERGY PERFORMANCE CERTIFICATES CONSULTATION This document includes the National Retrofit Hub’s response to the HEM:EPC consultation, which was produced based on our research and industry engagement over the last three years, and workshop feedback from our working group, cross-cutting theme members and other collaborators. We hope this document will be useful for others looking to engage with the consultation, understand its relevance, and make their own responses. We have drafted responses to questions most relevant to the NRH’s work and mission. We have not provided answers to questions 3 and 14-17, however these may be relevant to you and your organisation, so please do take a look at them. We encourage potential respondents to read the consultation and respond to as many or as few questions that are relevant to them and their work.
CONTEXT The Home Energy Model: Energy Performance Certificates consultation opened 21 January 2026 and will close on 18th March. The consultation applies to England and Wales. The Home Energy Model (HEM) is a general-purpose simulation of energy use in a dwelling. It is used to calculate energy performance. ‘Wrappers’ are used to apply HEM for specific assessment, eg: for Part L compliance or to produce Energy Performance Certificates (EPCs). The HEM:EPC wrapper will replace both SAP and rdSAP. The consultation covers two topics: •
The proposed expansion of HEM to permit calculations based on on-site inspection of existing dwellings.
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How EPC metrics should be calculated and translated into new EPC bands.
This is important because: •
The potential to include more real-world data could lead to more accurate EPCs and better performance outcomes.
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The boundary between C and D ratings, in particular, impacts the standards homes in the private and social rented sector need to meet under the Minimum Energy Efficiency Standards and grant funding eligibility. Access to green finance can also be influenced by a home’s EPC bands, and future policy, regulation and funding will likely make requirements based on EPC bands.
MHCLG and DESNZ are in the process of reforming EPCs. This will include a change to the metrics within EPCs. Existing metrics will be replaced by four new headline metrics: fabric, The National Retrofit Hub is a Community Interest Company (CIC) limited by guarantee without share capital. Company no. 16834381, registered in England at Lelliott & Co Limited, Heath Place, Ash Grove, Bognor Regis, West Sussex, PO22 9SL.