Home Energy Model: replacement for the Standard Assessment Procedure (SAP)
Read the full outcome
Detail of outcome
Update: 10 February 2026
In the final stages of internal assurance we have decided to delay the launch of the Home Energy Model (HEM) to ensure that when it does go live, it is as robust as possible and delivered to the highest possible standard. This means that HEM will no longer launch at the same time as the Future Homes Standard (FHS).
The wider FHS package remains on track for Q1 2026, so SAP 10.3 will initially be the sole approved methodology. HEM is expected to follow after at least a 3‑month delay.
The government is committed to refining the Home Energy Model (HEM) to support net zero and housing goals. HEM together with reforms to the Future Homes Standard (FHS) will provide a new methodology for demonstrating compliance.
To ensure a smooth transition, both HEM and a version of SAP (the Standard Assessment Procedure, currently used to assess the energy performance of homes) will be available for a limited period. This dual running allows industry and stakeholders time to adapt, ensures continuity, and enables further validation of the new model before it becomes the sole methodology.
In 2026, we will explore integrating HEM into Energy Performance Certificates (EPCs), aiming to improve clarity and usefulness for households and industry.
The HEM engine will continue to be developed via the Energy Calculation as a Service (ECaaS) platform, delivering a fast, cloud-based tool available by autumn 2026 to support regulation and third-party applications. Updated technical documentation and validation reports will accompany the next release, highlighting improvements and expanded real-world testing.
Detail of feedback received
We received 120 responses to this consultation, from:
- organisations
- trade bodies
- industry professionals
- academics
- members of the public
While not every individual point is addressed here, all feedback has been carefully analysed and has shaped our approach.
Original consultation
Consultation description
Update: 1 March 2024
We have extended the consultation closing date to 27 March 2024 (from 6 March).
The Standard Assessment Procedure (SAP) is the methodology currently used by the government to estimate the energy performance of homes across the United Kingdom. It is of critical importance to the delivery of our housing and climate change objectives.
The Home Energy Model will replace the SAP for the energy rating of dwellings.
We are consulting on the Model while it is still at a formative stage, so that industry can participate in the development process. This consultation:
- summarises the development and validation work undertaken to date
- invites feedback to enable further model development in advance of its introduction
We will also hold a series of engagement events throughout the consultation period: email homeenergymodel@energysecurity.gov.uk to find out more.
The consultation will be of interest across the built environment sector.
It is part of a wider government package of material relating to the Home Energy Model and the Future Homes Standard. See The Home Energy Model.
Read our consultation privacy notice.
Documents
Updates to this page
-
Summary of responses and government response published.
-
Consultation closing date extended to 27 March 2024.
-
First published.