Where is the Home Energy Model?
It has been three months since the release of the Future Homes Standard and the associated SAP 10.3 methodology. This article looks at the latest on the delivery of HEM for the Future Homes Standard (HEM:FHS) and what we know so far.
What is the Home Energy Model?
The Home Energy Model is a full replacement for the current Standard Assessment Procedure. Developed using modern industry standards and validated against real‑world performance data, it represents a step change in how the energy performance of homes is assessed.
Like SAP, the Home Energy Model will sit at the heart of a wide range of government policies, making it a critical tool for delivering the UK’s housing and climate ambitions. As the government consultation put it, it is “a new name for a new methodology”.
Find out more about HEM and how it works below.
FIND OUT MORE ON HEMSAP to HEM – a phased transition
2023 – Where we started
Since the Future Homes Standard consultation in 2023 Government have been working on developing the HEM calculation engine and associated Future Homes Standard wrapper.
2025 – Dual compliance methods confirmed
In June 2025 MHCLG published a statement confirming that both SAP and HEM would be able to be used to demonstrate compliance with the Future Homes Standard once launched. This pragmatic step was to ensure a smooth transition to HEM and give time for the model and surrounding ecosystem to mature until it was ready to take over from SAP.
Feb 2026 – SAP to be the only route to compliance on the launch of the FHS
In February 2026 a further announcement was made. This confirmed SAP would be the only method for demonstrating compliance initially once the Future Homes Standard was released. This was due to issues found in the final stages of internal assurance of HEM and to ensure it was robust and delivered to the highest possible standard.
Mar 2026 – Release of the Future Homes Standard
On the 24th March 2026 the Future Homes Standard and SAP 10.3 were launched. In the Future Homes Standard consultation responses, there were further details of how HEM would be introduced as an approved methodology;
- At least three months after the release of the Future Homes Standard HEM would be recognised as an approved methodology.
- This would commence a two-year dual running period where SAP and/or HEM can be used to demonstrate compliance with the Future Homes Standard.
- Following this two-year period, and when Government are confident, HEM will take over from SAP for all work commenced after this point.
Our understanding is that this transition will be applied on a site wide basis, unlike the transitional arrangements for Building Regulations which are applied on a per plot basis. This is to ensure that a scenario where parts of sites are on differing methodologies does not occur.
What is the latest on HEM?
Government are broadly satisfied that the model and wrapper are finished to enable HEM to calculate compliance to the Future Homes Standard. This is being implemented onto the Government’s Energy Calculations as a Service (ECaaS) facility which schemes will need to connect to in order to generate compliance results, BRELs and next year EPCs.
The focus is now shifting to what is needed for the industry to be ready for the release of HEM. Of critical importance, is the need for comprehensive training materials, clear competency requirements and conventions for HEM to be deployed successfully. Government are currently liaising with accreditation schemes to undertake this work.
When can we expect HEM to be released?
Officially there is no fixed date for when HEM will be released to demonstrate compliance with the Future Homes Standard. Elmhurst are working closely with Government to ensure all crucial steps are completed before HEM can be successfully deployed to the industry.
What about Elmhurst’s Design HEM application?
Elmhurst’s application for HEM, known as Design HEM, continues to be developed. Over the past few months Government have achieved some important milestones to aid this such as completion of the HEM version used at ECaaS and FHS wrapper contents. We are still awaiting some vital components that are needed to complete an assessment such as HEM PCDB and BREL details from ECaaS.
As we get nearer to the release of Design HEM we will share more details of our application BETA testing opportunities for those members that registered and associated training options.
FIND OUT MORE ON DESIGN HEMNew Build Dwellings Manager Jason Hewins commented;
“Since the release of the Future Homes Standard assessors have been using SAP 10.3 to assess the impact on designs of the new regulations. However, many parts of the industry are awaiting the release of HEM in order to compare compliance standards with SAP 10.3. Many stakeholders are concerned that HEM will provide different performance standards for compliance than SAP and we know Government have undertaken work to ensure this risk is reduced as much as possible.
In order to deliver a smooth transition to HEM its vital the model and its surrounding ecosystem is fully completed. We are in regular meetings with Government and will continue to ensure our members are updated on progress where possible.
In regards to Elmhurst’s Design HEM application, our software teams are working hard on development and making good progress, and we are looking forward to sharing more details on the application soon.”