top of page

SBEM Calculations


Packages are available for Design stage, As Built Stage and the final EPC certificate..

We can turn around reports in a few days as no site visit is required. Elmhurst Accredited (EES017715)

Call 07510 090 633 or email

Part L2A

New Construction

Part L2B


Part L2B



BRUKL Reports (also referred to as SBEM calculations or reports) can either be generated using SBEM (Simplified Building Energy Modelling) or for more complex buildings that take into consideration daylighting and seasonal variances, DSM (Dynamic Simulation Modelling).


To complete the necessary calculations and generate the relevant reports, we require some basic information about the building. A full list will be provided upon instruction.

This page deals with BRUKL Reports as requested by Building Control. More information on our BREEAM services can be found here.


SBEM Calculations


We will require to you complete a simple form and provide some relevant supporting evidence (such as product brochures). We will only ask you to provide relevant information.

  • HVAC info – location/heat recovery, make/model etc.

  • Lighting loads (w/m2 @ 100 LUX, or, lumens/watts either per zone or average for building)

  • Hot water systems (storage tank make/model/size)

  • U-Values – walls, floors, roofs, glazing, doors

  • Plans and elevations – must include measurements (PDF only. Do not provide AutoCAD files)

  • General overview of mechanical ventilation – location, heat recovery, make/model etc

  • External elevations / conceptual drawings

  • Air test Certificate if >500m2 (or if <500m2 and permeability is being declared as less than 15)

  • (optional but helpful) Photographs of the project, during construction and upon completion


Note, for Shell and Core / Design Stage, as a minimum we require only floor plans and elevations to produce either an EPC or an SBEM report. However, any M&E specifications or U values that have been recommended (in the absence of any information provided) within the calculations should be implemented as a minimum during fit out.

Note on the EPC

We calculate the final EPC rating by converting the SBEM model into an audit compliant EPC. Ideally the AS BUILT SBEM calculation will not require alignment to the Non-Domestic EPC Conventions prior to conversion.

Unlike the SBEM reports, EPCs are auditable. Where clear and convincing evidence is not provided we have no choice but to follow the guidance provided within the Non-Domestic EPC Conventions and use approved default values in the calculation (otherwise the EPC will fail audit).

Default values (especially for U Values, lighting (lum/w), HVAC and hot water) will typically underperform the real life scenario and will ALWAYS have a detrimental effect on the EPC/SBEM rating.

We always endeavor to achieve the best possible EPC rating, however please understand that we are unable to guarantee an EPC rating for your building at any stage. A poor rating is either a product of weak design or poor evidence. We will clearly tell you what we need in order to get the most out of the scoring process.

L2A - New Build

Part L2A - New Buildings


All Non-Domestic buildings require SBEM calculations at both design and completion stage unless they would normally be exempt from Part L (and therefore Commercial EPC requirements). These would include:

  • Places of worship

  • Stand-alone units of less than 50m2

  • Listed buildings that are unable to comply with Part L due to planning restrictions

  • Temporary buildings with a planned lifecycle of less than 2 years

L2B - Extensions

Part L2B - Extensions


SBEM calculations are required where the extension part has a floor area greater than 25% of the floor area of the original building and a gross internal area greater than 100m2.

An SBEM will also be triggered if the glazing areas are greater than those shown in the table below, and if so then the calculations will need to show that the extension is as energy efficient (with the same, or lower carbon emissions) than the equivalent extension but with compliant glazing areas.

The calculations will only apply to the extension area but may take into consideration the existing buildings core services.



Essentially all conversions to non-dwellings require an SBEM Calculation in order to comply with Part L2b of the Building Regulations (or a regional variant). A conversion typically occurs as a result of a ‘Material Change of Use’, where the purpose or use of the building is altered.

Some examples of what is considered a ‘Material Change of Use’ are provided by Building Regulations/Standards:

  • The building is used as a hotel or boarding houses where it was previously not

  • The building is used as an institution or school where previously it was not

  • The building is used as a public building where previously it was not

  • The building is used as a dwelling where previously it was not

L2B - Convesions
bottom of page