EPC reform is putting hot water under the spotlight, and water-efficient showers have never mattered more
Energy Performance Certificates (EPCs) in England and Wales are changing.
From 2026, EPC assessments are expected to transition to the Home Energy Model (HEM), a methodology designed to better reflect how homes and buildings actually perform, the energy they use, and their real running costs
At the centre of these reforms is a shift away from theoretical scores and towards real-world energy demand, including the energy used to heat water. For homeowners, housebuilders and retrofit professionals, this brings water efficiency and shower performance firmly into focus.
What’s changing and when?
EPCs will be generated using a methodology called the Home Energy Model (HEM), replacing the current SAP and RdSAP approaches. HEM uses more detailed modelling to assess energy use over time, providing a clearer picture of how buildings perform in everyday use.
Rather than relying on a single headline rating, new EPCs will present clearer performance metrics, including heating and hot water efficiency and estimated running costs. Government consultation is underway, with new EPC methodology expected to be introduced in late 2026, alongside a transition period where current ratings remain visible.
Crucially, this new approach places greater emphasis on ongoing energy demand, particularly the energy required to heat water for daily activities such as showering.
Why EPC reform matters
Heating and powering buildings account for almost a quarter of UK carbon emissions. A significant share of this comes from hot water use, with showers representing one of the most frequent and energy-intensive demands in both homes and commercial buildings.
The reformed EPC framework is designed to provide clearer information, support better design and retrofit decisions, reduce energy bills and align the built environment with the UK’s net zero targets. By focusing on how energy is actually consumed, EPCs are becoming a tool for demand reduction, not just technology choice.
These reforms are being led by the Department for Energy Security and Net Zero as part of wider plans to improve building performance and affordability.
What EPC reform means for rented and social housing
Currently, privately rented homes in England and Wales must meet a minimum EPC rating of E to be legally let. However, government policy continues to push towards higher building performance standards, and future tightening of minimum requirements remains likely.
As EPCs transition to the Home Energy Model (HEM), building performance becomes more closely linked to real energy demand and running costs, not just headline efficiency scores. For landlords and housing providers, improving efficiency now helps future-proof properties against potential regulatory changes while reducing operating costs.
This means EPC performance is no longer just about heating systems or insulation upgrades. Every source of daily energy demand matters, particularly showers, which are used frequently and at scale across housing portfolios.
Why water efficiency now directly affects EPC compliance
Hot water production is one of the most consistent energy loads in a building. As EPCs evolve under HEM, the energy required to heat water is captured more accurately, making water-efficient fixtures increasingly relevant to overall performance.
Reducing hot water demand:
– lowers energy consumption
– reduces carbon emissions
– improves EPC outcomes
– supports long-term regulatory readiness
In simple terms, using less hot water means using less energy.
Where Kelda fits under the Home Energy Model
The introduction of HEM represents a significant shift in how innovative water-efficient technologies are recognised within EPC assessments.
Under the new methodology, Air-Powered™ showers are recognised as a distinct shower category, rather than relying solely on Appendix Q routes within SAP. This makes Kelda showers easier and more consistent to model, reducing uncertainty for assessors and specifiers.
For housing providers, developers and retrofit teams, this means:
– clearer EPC calculations
– improved confidence in predicted performance
– fewer barriers to specification
Kelda’s Air-Powered™ showers reduce water use by up to 55%, directly lowering the energy required to heat water. These savings are more accurately reflected within EPC assessments, supporting stronger building performance while maintaining a high-quality shower experience.
Why this matters now
As EPC reform moves from consultation to implementation, decisions made today will influence how homes perform tomorrow.
Technologies that:
– reduce demand at source
– are clearly recognised within HEM
– support long-term building performance
will play an increasingly important role in future-proofing homes and housing portfolios.
In summary
- EPC reform will transition to the Home Energy Model from 2026
- EPCs will increasingly reflect real energy use, including hot water demand
- Minimum rental standards may tighten over time, increasing pressure to improve efficiency
- Water efficiency directly supports energy performance and lower running costs
- Kelda Air-Powered™ showers are recognised within HEM and reduce hot water demand at source
- Reducing hot water use helps lower bills, cut carbon and future-proof buildings
Future-proof your building performance with Kelda Showers
Speak to our team about water-efficient shower solutions today.
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