What is a BREL Report?

The document that proves a new-build dwelling complies with Part L

BREL stands for Building Regulations England Part L. A BREL report is the document produced by an accredited OCDEA to demonstrate that a new-build dwelling complies with Part L of the UK Building Regulations. It bundles the SAP calculations, the Appendix B photographic evidence, and the assessor's declaration into one document.

No BREL sign-off, no handover. It's that simple.

What goes in a BREL report

A BREL report brings together:

  • Project and plot identification - site address, plot reference, dwelling type
  • Design-stage SAP results - the calculation run before construction, showing the target compliance
  • As-built SAP results - the updated calculation using what was actually installed
  • Fabric performance evidence - U-values, insulation specifications, thermal-bridging details
  • Appendix B photographic evidence - section-by-section photos with GPS and timestamps
  • Commissioning certificates - for heating, hot water, ventilation, and any renewables
  • Airtightness test results - typically from a pressure test on the finished dwelling
  • OCDEA declaration - the assessor's confirmation that all the above adds up to Part L compliance

Building Control - whether the local authority or a private Approved Inspector - relies on the BREL as their record of Part L sign-off.

Who produces the BREL report

Only an accredited OCDEA can produce a BREL report for a new-build dwelling. A standard DEA doesn't have the on-construction qualification required. Accreditation is held through Elmhurst Energy, Stroma Certification, Sava, Quidos, or ECMK, and the OCDEA's accreditation body is named on the report.

When a BREL is required

For every new dwelling in England. One BREL report per dwelling, not per site. So a development of 20 houses needs 20 individual BREL reports, each with its own SAP calculation and its own Appendix B evidence package.

Scotland uses its own equivalent procedures under Section 6 of the Scottish Building Regulations; Wales is aligned with England but with separate versions of Part L.

Buildsnpper produces the Appendix B evidence package that feeds straight into the BREL. Section-by-section photos, GPS and timestamps automatic, one-tap report to your OCDEA. From £6.67 per month, 14-day free trial. See how it works.

BREL and the Performance Gap

The Performance Gap is the difference between a dwelling's designed performance (from the design-stage SAP) and its actual as-built performance (from the as-built SAP and what can be verified on site). The BREL report is where this gap gets flagged or closed.

Under the Future Homes Standard, regulators are paying more attention to the Performance Gap. Which means OCDEAs are paying more attention to whether the Appendix B photos actually back up the as-built SAP. Weak evidence means a more conservative as-built calculation, which means a worse EPC band and potentially a non-compliant dwelling.

Frequently asked questions

What does BREL stand for?

BREL stands for Building Regulations England Part L. It's the standard report used to demonstrate new-build dwelling compliance with the Part L energy efficiency regulations.

Who produces a BREL report?

An accredited OCDEA (On Construction Domestic Energy Assessor) produces the BREL report. Only OCDEAs have the on-construction qualification required to sign off new-build Part L compliance.

What is in a BREL report?

Design-stage SAP results, as-built SAP results, fabric performance evidence, Appendix B photographic evidence, commissioning certificates, airtightness test results, and the OCDEA's declaration of compliance.

When is a BREL report required?

A BREL report is required for every new dwelling in England. One report per dwelling. Building Control signs off Part L compliance based on the BREL before handover can complete.

How long does a BREL report take to produce?

Most of the work is front-loaded at design stage (design SAP) and spread through construction (reviewing photo evidence). The final as-built calculation and BREL production typically takes a few days once all site evidence and commissioning certificates are in.

What's the difference between a BREL and an EPC?

The BREL is the compliance document for Building Control, used to sign off Part L. The EPC is the consumer-facing certificate showing the dwelling's energy rating (A-G). Both come out of the same SAP calculation for a new build - the OCDEA lodges the EPC on the Energy Performance of Buildings Register once the BREL is complete.

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