An EPC survey should check the evidence before recommending work.

We distinguish a standard assessment from an evidence-led EPC survey, then check assumed inputs, accepted documents and whether airtightness or U-value testing can answer a material question.

Energy assessor carrying out airtightness testing in a British home
Evidence firstTesting is recommended only where a measured value could change the assessment.
Scoped before bookingYou receive a clear testing scope, the evidence it is intended to establish and the payment stage before you commit.
Property specificNo promise of a band change is made before the existing certificate and building are reviewed.
What the certificate may miss

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.

01

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 suitability
02

U-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 value
03

Documentary 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 assessor
04

New 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
Specialist inspecting building fabric during an EPC survey
When testing makes sense

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.

Property guide

An EPC survey should check the evidence before recommending work.

A standard EPC assessment records the property using the approved methodology and evidence available to the assessor. A specialist EPC survey goes further where an assumed construction, missing document or material input may be holding the rating back.

Accepted documentary evidence, airtightness testing or in-situ U-value testing can answer a defined assessment question. We explain likely cost and relevance first, and recommend testing only where the result can credibly affect the route to C.

No C No Fee route

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.

01

Certificate review

We inspect the current rating, recommendations and assumed or not-rated entries.

02

Testing plan

The assessor confirms what can be measured and what evidence is required.

03

Property visit

Approved testing and the EPC assessment are carried out at the property.

04

Lodged EPC

The service charge becomes due when the new certificate is lodged as agreed.

Know the boundary

Measured evidence, not a manufactured result.

An EPC rating cannot be guaranteed in advance. The outcome depends on the property, the accepted evidence and the approved methodology in force when the assessment is lodged.

Specialist testing questions

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.