Before you upgrade the property, improve the evidence.
When an EPC contains assumed or not-rated values, specialist testing can replace generic defaults with measured building performance. For the right D-rated property, that can be the lowest-cost route to a more accurate result.
An EPC is only as strong as the evidence available to the assessor.
Standard EPC assessments use approved conventions. Where construction details or performance cannot be evidenced, the methodology may require a default or assumed value. That does not mean the assessor has made a mistake. It means the certificate is working with limited evidence.
Airtightness testing
A blower-door test measures air leakage through the building envelope. It can provide property-specific evidence where the assessment route accepts a measured result.
Check suitabilityU-value testing
In-situ testing can help establish how a wall, roof or floor performs where construction is uncertain and the current EPC relies on a conservative assumption.
Review an assumed valueDocumentary evidence
Building-control records, guarantees, invoices and installation certificates may support existing improvements. We explain what evidence is useful before a site visit.
Ask an assessorNew EPC lodging
The measured evidence must be used within an appropriate assessment and lodged correctly. Testing alone does not change the register.
Find an EPC
Use a test to answer a real assessment question.
Specialist testing is not a shortcut and it is not appropriate for every home. It is most useful when the current EPC shows a material assumed value, the building is likely to perform better than that default and a measured result can be accepted within the approved methodology.
- 01The property is close enough to the target for better evidence to matter.
- 02The relevant fabric element can be tested safely and representatively.
- 03Existing records are missing or insufficient to replace the default.
- 04The likely cost is lower than installing measures that may not be needed.
If the evidence is unlikely to change the outcome, we recommend a different route rather than selling an unnecessary test.
An EPC assessment is strongest when the building evidence is complete.
A standard EPC survey records the property using the approved methodology and evidence available to the assessor. Where construction or performance cannot be evidenced, conventions may require an assumed value that does not fully reflect the building.
Specialist airtightness, U-value or documentary evidence can be useful when a specific entry is material and an accepted measured result may change the assessment. Testing is recommended only where it answers a real EPC question.
A clear process from current certificate to lodged result.
The free initial review checks whether specialist evidence is a credible route. If it is, the property is surveyed, suitable testing is completed and the EPC assessment is updated using the available evidence.
Certificate review
We inspect the current rating, recommendations and assumed or not-rated entries.
Testing plan
The assessor confirms what can be measured and what evidence is required.
Property visit
Approved testing and the EPC assessment are carried out at the property.
Lodged EPC
The service charge becomes due when the new certificate is lodged as agreed.
What landlords usually ask first.
These answers set realistic expectations before a property is booked for testing.
No. Testing only helps when a relevant assumed value is conservative and the measured performance is better. Some properties will still need physical improvements.
Domestic EPC conventions require assessors to use approved defaults where construction or performance cannot be evidenced. A standard visual survey cannot establish every hidden detail.
The property address or EPC report reference, plus any invoices, guarantees or records for insulation, windows, heating and renewable systems.
Possibly. If the building is suitable and grant support is available, a well-designed heat pump system may be more valuable than specialist testing alone. The initial review compares both routes.
Let the certificate tell us what to investigate.
Send the current EPC for a free initial review. We will tell you whether specialist testing, a heating route or a broader upgrade plan deserves the next step.