Lock in your EPC rating under today’s rules
Energy Performance Certificates (EPCs) are currently assessed using the RdSAP 10 methodology.
If your property achieves an EPC C rating today, that certificate is valid for 10 years from the date of issue.
During this period, your property may continue to be assessed against the standards in place at the time the certificate was issued — even if future methodologies change.
This is often referred to as “Grandfather Rights”.
What is changing?
The UK government is developing a new assessment framework called the Home Energy Model (HEM), which is expected to replace RdSAP from around 2027.
HEM is designed to be more detailed and data-driven, using additional property inputs and more advanced modelling.
While this should improve accuracy, it may also make achieving certain EPC ratings — including EPC C — more technically demanding.
Early indications suggest that some properties could require more comprehensive upgrades, improved evidence, or higher-performing systems to achieve the same rating under HEM.
Why timing matters
- Achieving EPC C under current rules may require fewer or lower-cost improvements
- Your EPC certificate is valid for 10 years once issued
- Future methodology changes may increase the level of detail and evidence required
- Some upgrade pathways may become more complex or expensive over time
What this means for landlords
If your property can reach EPC C today, securing that rating now could help you plan ahead with greater certainty.
It may also reduce the likelihood of needing more extensive upgrades in the near future if assessment standards become stricter.
While future policy and enforcement may evolve, acting earlier gives you more flexibility and control over how and when improvements are made.
In simple terms:
Reach EPC C under today’s rules → keep that rating for up to 10 years → reduce the risk of stricter and more costly requirements later.
