Energy Systems Catapult published its response to the Department for Energy Security and Net Zero (DESNZ) consultation on the Home Energy Model methodology on 1 April 2026. The consultation covers the methodology for assessing existing dwellings and producing new Energy Performance Certificate metrics1.
The Catapult said EPCs should draw on measured performance rather than modelled assumptions alone. Its response states:
"Energy Performance Certificates (EPCs) should integrate real-world data on fabric performance and low-carbon technologies to improve accuracy, drive innovation, and provide clear, outcome-focused energy cost information for consumers."
Three key points are set out in the response. First, real-world data should be embedded into EPC assessment wherever possible, using Smart Meter Enabled Thermal Efficiency Ratings (SMETERs) and monitoring of low-carbon technology efficiency. Second, the new metrics should be designed around outcomes rather than stipulating specific technologies, which the Catapult says supports flexibility and the low-carbon solutions best suited to both the property and the wider energy system. Third, EPCs should give clear, usable consumer information so householders can make informed decisions about their property and compare properties meaningfully1.
The response does not set out proposed metric values, thresholds or a timetable for their introduction. No figures for accuracy improvements, cost or delivery timescales are given in the published response1.
Why it matters for households
An EPC is the document that records how a home performs and is used in EPC regulations and reform, including rules that apply when a property is sold or let. The Catapult's argument is that the rating should reflect how a home actually performs, not only how it is modelled. For a household, that distinction matters where a certificate's score does not match the bills or comfort experienced in the property.
The second point concerns technology choice. Metrics that reward outcomes rather than named technologies would leave the route to a given rating more open, which bears on decisions about insulation, heating and controls. The third point concerns information: the Catapult wants certificates that allow one property to be compared with another on a like-for-like basis.
The Home Energy Model is the intended replacement for SAP, the methodology behind current EPCs. Its design therefore shapes what a certificate will say about a home's energy independence, and how much weight that statement carries with lenders, landlords and installers. The consultation sits within the wider process of energy consultations through which DESNZ sets home energy policy.
What happens next
The response was published on 1 April 2026. The source does not state when DESNZ will publish its response to the consultation, nor whether the Catapult's recommendations will be adopted. No next steps or dates have been reported1.
Sources1 cited
- Response to consultation on Home Energy Model methodology, es.catapult.org.uk