The Home Energy Model (HEM) and the Future Homes Standard (FHS) are changing how homes in England are assessed and built. If you own an existing home, no immediate action is required : the FHS applies only to new builds. However, the way your home's energy performance is measured is changing: the government has proposed that EPCs move from a single A–G rating to four separate metrics, and the underlying calculation is switching from SAP to HEM. If you are buying a new-build home, it will be built to much higher energy standards.
If You Own an Existing Home
The Future Homes Standard does not apply to existing homes. You are not required to retrofit your property, install a heat pump, or add solar panels. The changes that will affect you are:
Your Next EPC Will Look Different
From the second half of 2027 (delayed from the original October 2026 target), new EPCs will be calculated using the Home Energy Model instead of SAP/RdSAP. The government has proposed replacing the single A–G rating with four separate metrics (subject to the outcome of the EPC reform consultation):
| Metric | What It Tells You |
|---|---|
| Fabric Performance (A–G) | How well your walls, roof, floor, and windows retain heat |
| Heating System (A–G) | How efficient and low-carbon your heating is |
| Smart Readiness (A–G) | Your home's capacity for smart energy management |
| Energy Cost (£) | Estimated annual energy running costs |
Under the proposed system, buyers and tenants would see a much clearer picture of your home's strengths and weaknesses. If you have invested in good insulation, that would show clearly in the Fabric Performance metric, even if you still have a gas boiler. For a full guide to the new EPC system, see our EPC Changes for Homeowners page.
If You Have Gas or Oil Heating
Under the proposed EPC reform, properties with fossil fuel heating (gas, oil, LPG) would not achieve a C rating on the Heating System metric. This does not mean you have to change your heating system, but it may gradually influence property values as the market adjusts to any new EPC format.
Making Energy Improvements
If you are planning energy efficiency improvements, HEM's more accurate modelling means your investment will be better reflected in your EPC:
- Insulation improvements (cavity wall, loft, floor) would show clearly in the proposed Fabric Performance metric
- Heat pump installation would dramatically improve your Heating System rating under the proposed metrics. Planning rules have recently been relaxed: the one-metre boundary rule has been removed, and air-to-air systems now qualify as permitted development, making installation easier for more properties
- Solar PV will reduce your Energy Cost figure, with HEM properly modelling how much electricity you use on-site versus exporting to the grid. From mid-2026, plug-in solar panels (up to around 800 W) will be legal, offering a low-cost option for renters and flat owners
- Battery storage will be credited for the first time (SAP cannot model batteries at all)
- Smart controls would contribute to the proposed Smart Readiness metric
If You Are Buying a New-Build Home
New homes built after the FHS comes into force on 24 March 2027 will be built to significantly higher energy standards than current new builds. Here is what to expect:
| Feature | Current New Build (Part L 2021) | FHS New Build |
|---|---|---|
| Heating | Gas boiler | Heat pump (no gas connection) |
| Ventilation | Trickle vents or basic extract fans | Mechanical ventilation (dMEV or MVHR) with filtered fresh air |
| Windows | Double glazing | High-performance glazing (typically triple glazed) |
| Solar | Not required | On-site solar PV (functional requirement L3, with exemptions for impractical sites and high-rise flats) |
| Airtightness | Standard construction | Significantly tighter airtightness (notional dwelling assumes 3 m³/(h.m²) at 50 Pa) |
| Energy bills | Standard | Significantly lower than a typical existing home. Compared to a Part L 2021 new build, the difference may be marginal due to higher electricity unit costs |
What Living in an FHS Home Is Like
- No gas supply: no gas hob, no gas boiler. All energy comes from electricity (much of it generated by your own solar panels)
- Quieter and more comfortable: the enhanced airtightness and mechanical ventilation mean less outside noise and more consistent indoor temperatures
- Fresh air is mechanically controlled. Mechanical ventilation delivers filtered fresh air. Homes with MVHR recover heat from extracted air, improving efficiency further. You do not need to open windows for ventilation (though you still can)
- Lower energy costs than existing homes: the combination of a heat pump, solar PV, and excellent insulation means significantly lower running costs compared to a typical existing home, though the saving compared to a Part L 2021 new build may be marginal due to higher electricity unit costs
- Solar panels on the roof, generating free electricity during daylight hours, with any surplus exported to the grid
If You Are a Landlord
Landlords should pay particular attention to the proposed EPC reform. The current Minimum Energy Efficiency Standards (MEES) require rental properties to achieve at least an E rating. The government has consulted on raising this to C, and the proposed four-metric system may change how minimum standards are defined.
- Under the proposed EPC reform, properties with gas boilers would score D or below on the Heating System metric, which may become relevant if MEES applies to individual metrics
- The proposed Fabric Performance metric would provide a clearer basis for targeting improvements
- The government has not yet confirmed how MEES would work with the proposed four-metric framework
For full details on EPC changes, including the timeline and what actions to consider, see our EPC Changes for Homeowners page.
Explore Homeowner Guides
EPC Changes for Homeowners
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HEM and Your Home
Plain English guide to what HEM means for your home, bills, and EPC.
New EPC Metrics Explained
Full breakdown of the four new EPC headline metrics.
EPCs & HEM
Complete guide to how EPCs are changing under HEM.
Frequently Asked Questions
Does the Future Homes Standard affect my existing home?
No. The Future Homes Standard applies only to new-build homes in England. You are not required to retrofit your existing home. You can continue to use and replace your gas boiler. However, HEM will eventually be used for existing home EPCs, so your next EPC will look different. The government has proposed four separate metrics instead of a single A–G rating, subject to the outcome of the EPC reform consultation.
Is my current EPC still valid?
Yes. Existing EPCs remain valid for 10 years from issue, regardless of when the new system launches. You only need a new EPC when selling or letting your property, or when yours expires. See our EPC Changes page for full details.
Is there a gas boiler ban?
No. There is no ban on gas boilers in existing homes. The FHS means new-build homes will need low-carbon heating (primarily heat pumps) because gas boilers cannot meet FHS carbon targets. But existing homeowners can continue to install, replace, and repair gas boilers. There is no requirement to switch to a heat pump in your current home.
What should I look for when buying a new-build home?
FHS homes (from March 2027 onwards) will include a heat pump, solar PV, mechanical ventilation (dMEV or MVHR), high-performance glazing (typically triple glazed), and enhanced insulation. Energy costs compared to a typical existing home will be significantly lower, though compared to a Part L 2021 new build the difference may be marginal due to higher electricity unit costs. During the transitional period (March 2027 to March 2028), some homes may still be built to Part L 2021, so ask which standard applies.
Will the new EPC system affect my property's value?
The government has proposed a four-metric EPC that would provide more detailed performance information, which may influence buyer decisions. Under the proposed system, properties with fossil fuel heating would score poorly on the Heating System metric. Properties with good insulation would benefit from the separate Fabric Performance metric. The impact on values will likely be gradual as the market adjusts to any new format.
Related Pages
What is the Home Energy Model?
Comprehensive introduction to HEM: what it is and how it works.
Future Homes Standard
Full guide to the FHS and what it means for new homes.
How EPCs Are Changing
Detailed guide to the new EPC assessment process and transition.
Timeline & Status
Live tracker of HEM, FHS, and EPC reform milestones.