What Is a BRUKL Report?

A BRUKL report (Building Regulations UK Part L) is the formal compliance document that demonstrates a non-domestic building meets the energy performance requirements of Part L of the Building Regulations. It is produced by SBEM or approved Dynamic Simulation Modelling software and is required at both design stage and as-built (AD L2 2026).

Who needs a BRUKL report?

A BRUKL report is required for:

• All new non-domestic buildings
• Extensions to existing non-domestic buildings (where the extension has its own heating system or is over a certain size threshold)
• Certain types of building work, including major renovations and change of use where Part L applies

The report must be produced by a qualified Non-Domestic Energy Assessor (NDEA) registered with an accreditation scheme. The assessor level required depends on the building complexity – Level 3 for simple buildings, Level 4 for complex SBEM assessments, and Level 5 for Dynamic Simulation.

When is it required?

BRUKL reports are needed at two stages (AD L2 2026):

• Design stage – submitted with the building control application or initial notice, demonstrating that the proposed design meets Part L requirements
• As-built – submitted before completion, confirming that the building as actually constructed still complies. This accounts for any design changes made during construction

What does a BRUKL report contain?

A BRUKL report documents the energy performance calculation results, including:

• BER and TER – the Building Emission Rate compared against the Target Emission Rate
• BPER and TPER – the Building Primary Energy Rate compared against the Target Primary Energy Rate
• Building geometry and construction details – areas, U-values, thermal bridging
• HVAC system specifications – heating, cooling, ventilation, hot water
• Lighting specification and efficacy
• Renewable energy contributions (including solar PV)
• Air permeability test results (for the as-built report)

BRUKL vs EPC

A BRUKL report and an Energy Performance Certificate (EPC) are related but different documents:

• BRUKL – demonstrates Part L regulatory compliance; produced during the building control process; required by law for new buildings
• EPC – rates a building's energy efficiency on an A-G scale; required when buildings are sold, let, or constructed; based on the same SBEM calculation but presented differently

The as-built BRUKL data feeds directly into the EPC for a new building, so the two are typically produced together by the same assessor.

Connection to SBEM

The BRUKL report is the output of the SBEM calculation (or an approved DSM tool). The assessor inputs the building details into SBEM, which calculates the BER/BPER and compares them against the TER/TPER from the notional building. The resulting report is the BRUKL.

Need a BRUKL report?

If you need BRUKL calculations for your non-domestic project, visit Easy EPC for professional SBEM assessment and compliance support.