What is a
BREL report?
A BREL report — Building Regulations England Part L — is the compliance report for a new dwelling. It is produced twice: once at design stage and once as built, and the as-built version must be backed by photographic evidence of the construction.
BREL, in one paragraph
BREL stands for Building Regulations England Part L. The BREL report is the standard document used to demonstrate that a new dwelling complies with Part L of the Building Regulations. It is generated from the SAP calculation for the dwelling and signed by the developer or builder.
It exists in two versions, and both are needed:
- The design stage BREL report, signed before construction begins, confirming the designed dwelling meets the Part L targets.
- The as-built BREL report, signed at completion, confirming that what was built matches the design — and accompanied by the photographic evidence that proves it.
What a BREL report contains
The report is generated by SAP software from the dwelling's assessment, and sets out:
- The dwelling's Target Emission Rate (TER) and Dwelling Emission Rate (DER)
- The Target and Dwelling Primary Energy Rates (TPER and DPER)
- The Target and Dwelling Fabric Energy Efficiency figures (TFEE and DFEE)
- The fabric specification actually used: U-values, thermal bridging, air permeability
- The heating, hot water, ventilation and any renewable systems installed
- A declaration, signed by the developer, that the information is correct
The as-built report must reflect what was actually installed. Where the build deviates from the design — a different boiler, a change of insulation product — the as-built SAP and therefore the as-built BREL have to be updated to match.
The photographic evidence that goes with it
Since the 2021 edition of Approved Document L, the as-built BREL report has to be supported by a photographic record of the construction details that affect thermal performance, as listed in Appendix B.
The record needs:
- One photograph per unique construction detail, per plot, with close-ups where clarity is needed
- Geolocation and a date and time stamp on each image
- Images captured at the right stage, while the detail is still visible
The photographs go to the SAP assessor alongside the as-built data. Once the assessor is satisfied that the construction matches the design, they complete the as-built SAP assessment and produce the EPC.
This is the practical difficulty with BREL: the report itself is produced by software in minutes, but the evidence behind it has to be gathered over months, by people on site, before each detail is covered up.
BREL report questions
Who signs the BREL report?
The developer or builder signs it — at design stage before construction begins, and again on the as-built report at completion. The SAP assessor produces the report from the assessment; the declaration is the developer's.
What is the difference between a design stage and as-built BREL report?
The design stage report confirms the designed dwelling meets the Part L targets and is signed before work starts. The as-built report confirms what was actually constructed, and must be accompanied by the photographic evidence.
Does a BREL report expire?
The report is tied to the specific dwelling and its as-built assessment, so it is not time-limited in the way an EPC is. But if the build changes, the as-built SAP and BREL have to be reissued to reflect what was installed.
Can I complete a BREL report without photographs?
The report can be generated, but the as-built submission will not be accepted without the supporting photographic evidence. The SAP assessor needs it to complete the as-built assessment and issue the EPC.
Who takes the photographs for the BREL report?
Anyone working on the project on site can take them, though a named responsible person gives a more consistent record. They are required for sign-off, and are not taken by building control.
Evidence that keeps up with the build
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