SBEM Calculations

You need one for almost all new non-domestic builds. You also likely need one if you are:

– Extending an existing commercial building.
– Fitting out a “shell and core” unit (First Fit-out).
– Changing the use of a building (e.g. barn to office conversion).
– Replacing a “thermal element” (like a new roof or HVAC system) in a large building.

If your initial design fails to meet Part L compliance targets (BER exceeds TER), we don’t just send back a negative report. We work collaboratively with your architectural and M&E design teams to identify the most cost-effective remedial measures. Common fixes include adjusting U-values, upgrading lighting controls, improving airtightness targets, or incorporating renewable energy technologies like solar PV or air source heat pumps.

SBEM stands for Simplified Building Energy Model. It is a government-approved software method used to calculate the monthly energy required to heat, cool, ventilate and light a non-domestic building. It compares your “Actual Building” against a theoretical “Notional Building” to ensure you meet minimum carbon standards.

You need one for almost all new non-domestic builds. You also likely need one if you are:

– Extending an existing commercial building.
– Fitting out a “shell and core” unit (First Fit-out).
– Changing the use of a building (e.g. barn to office conversion).
– Replacing a “thermal element” (like a new roof or HVAC system) in a large building.

SAP (Standard Assessment Procedure) is used exclusively for domestic residential properties – houses, flats and apartments.

SBEM (Simplified Building Energy Model) is used for non-domestic commercial properties – offices, retail units, warehouses, schools, industrial facilities and mixed-use developments.

If your project has both a residential and a commercial element, you’ll typically need both assessments run in parallel.

An SBEM Calculation is the underlying methodology used to demonstrate Part L Building Regulations compliance at both the design and completion stages of a build or fit-out.

A Commercial EPC (Energy Performance Certificate) is the final public-facing certificate generated directly from the completed “As-Built” SBEM model. It grades your building’s energy efficiency on an A+ to G scale, which is legally required to sell, let, or lease a commercial property.

Getting the underlying calculation right matters more than it might look: switching a listed venue’s assessment onto the correct methodology took Walton Castle’s rating from a failing F to a strong D.

When a commercial building is constructed without internal fit-outs (a “Shell and Core” build), an initial SBEM calculation is completed based on baseline assumptions for lighting and HVAC. Once an incoming tenant or developer carries out the First Fit-out, a secondary SBEM calculation (Fit-Out SBEM) is legally required to verify that the actual installed lighting, heating, and ventilation systems comply with Part L Volume 2. We’ve worked through exactly this sequence for an eight-unit commercial site at a enterprise park in Dorset – Design Stage SBEM for each shell-and-core unit, then Fit-Out SBEM as individual units were tenanted.

To get an accurate rating, we need:

– Geometry: Floor plans, elevations and sections.
– Fabric: U-values for walls, floors, roofs and windows (G-values).
– Systems: Details on HVAC (Heating, Ventilation, Air Conditioning), lighting efficiency (lumens/watt) and hot water storage.
– Renewables: Any solar PV or heat pumps included in the design.

The primary output is the BRUKL Report (Building Regulations UK Part L).

– Design Stage BRUKL: Submitted to Building Control before construction to prove the design works.

– As-Built BRUKL: Submitted after construction to prove the building was built correctly. This is also used to generate your Commercial EPC.

Yes. The Design Stage SBEM calculation is performed entirely using your project’s architectural drawings, M&E specifications, and technical documentation. For the As-Built stage, while the modelling is done digitally, site evidence (such as air permeability test certificates and commissioning certificates) or an on-site audit will be required to verify that the final build matches the initial specification. On some projects the two go hand in hand – for St Werburghs City Farm, we paired on-site diagnostic testing with SBEM modelling under the PAS 2038 methodology to build a full picture of the buildings’ performance.