Future Homes Standard 2025 Round-Up: SAP, HEM and What’s Coming Next
Throughout this year, we have reported on announcements regarding the Home Energy Model (HEM) and SAP, particularly in relation to the Future Homes Standard. With the end of the year fast approaching, we wanted to provide an update on our current position, latest developments and what’s coming next.
Where is the Future Homes Standard?
Throughout 2025 the government have stated that the Future Home Standard will be published by the end of the year. However, in recent weeks this has changed to “in the coming months”. So, we still have no firm date for when the Future Home Standard will be issued but we are expecting this to take place early next year.
Design SAP 10.3 achieves BRE approval
We have recently received BRE approval for the SAP 10.3 engine within our Design SAP 10 application. SAP 10.3 is a modified version of the current SAP 10.2 methodology that is currently used for Part L 2021. SAP 10.3 uses the Future Home Standard notional dwelling, revised primary energy and carbon factors to calculate compliance with the Future Home Standard.
Our updated Design SAP 10 application, with SAP 10.3 changes incorporated, will be released as soon as the Future Homes Standard is published. We’ll be working on resources to help members get up to speed on any changes and will share these as soon as we can.
The Home Energy Model: Still in Progress
Earlier in the year Elmhurst provided members with access to a test version of MHCLG’s user interface, built on the FHS wrapper and HEM engine version 0.34. This trial facility gave assessors an early look at what the MHCLG HEM user interface might feel like and helps them familiarise themselves with the principles. Whilst this tool is still available, it has not changed since its initial release in August.
Elmhurst are currently developing a new application using the Home Energy Model and Future Homes Standard assessment wrapper. Our application will connect to MHCLG’s Energy Calculation as a Service (EcaaS) facility which will host a version of HEM to be used to calculate compliance with the Future Homes Standard. It will also have a facility to be able to import data from our Design SAP 10 application. This will be crucial reducing the need to re-enter existing calculations during the dual running period of SAP and HEM.
Find out more about how HEM works here >
Points Still Awaiting Clarity
While development is progressing, several important areas remain under review: These include:
- The FHS wrapper has been completed but is not yet publicly available.
- Whilst Elmhurst believe existing OCDEAs will need some form of upskilling to use HEM this has not been confirmed by Government.
- The HEM PCDB is under development and will be accessed via ECaaS. However, we do not know what information we will be able to display in our HEM application.
- The formation of a conventions group to ensure consistency across the industry.
- The time period of dual running of both SAP 10.3 and HEM has yet to be defined including the rules around transitioning solely to HEM.
- Details around version control for the HEM methodology used for the ECaaS facility. Should a change need to be made or a bug fixed how will this be completed in a manner to minimise disruption to the industry?
What This Means for Assessors
The announcement earlier this year that both SAP and HEM could be used for compliance initially created some uncertainty across the industry. As we move closer to the launch of the Future Homes Standard, it is clear that HEM still requires further development before it is ready to be used at scale.
SAP 10.3 will be ready for immediate use through our Design SAP 10 application. This provides assessors with a familiar, trusted methodology that can be relied upon as soon as the Standard is published. For the industry, this continuity means there will be no gap in compliance tools: assessors will be able to deliver robust, accurate assessments while preparing for the longer-term transition to HEM.
Home Energy Model Theory Training
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