What are SBEM Calculations?

Don't know what SBEM calculations are but need a quick and easy explanation? Look no further - we explain exactly what they are, why you should care about them and more in this comprehensive guide.

SBEM or Simplified Building Energy Model is an essential compliance tool that ensures non-domestic buildings meet the energy efficiency requirements and carbon emissions targets of building regulations. Think of it as the non-domestic counterpart of SAP calculations, only more targeted for commercial buildings.

If you’re planning on new-build projects, extensions, refurbishments, or retrofits of buildings that aren’t dwellings, SBEM calculations are a must-have requirement. They’re the key to complying with building regulations and making sure your building is energy-efficient, sustainable, and cost-effective in the long run.

What does SBEM cover?

SBEM or Simplified Building Energy Model Calculations is developed by the BRE or Building Research Establishment. SBEM calculations analyze various aspects of your building specifications to ensure compliance with Building Regulations Part L. 

These elements include external wall, floor, and roof constructions, glazing and door specifications, heating and cooling systems, hot water systems, ventilation systems, lighting, air permeability, and renewable technologies. Trust in the accuracy and thoroughness of SBEM calculations to assess and optimize your building’s energy efficiency.

Simplified Building Energy Model (SBEM) calculations accurately predict the energy efficiency and carbon emissions of new commercial buildings. These calculations consider factors such as insulation, solar gains, air tightness, thermal bridging, heating efficiency, ventilation fan efficiency, low energy lighting, and renewable energy options. 

By utilizing architect’s drawings and a combination of these factors, the SBEM calculation can forecast energy consumption and carbon emissions for proposed non-domestic buildings. The software sets a Target Emission Rate (TER) for carbon emissions per square meter of floor space per year (kgCO2/m2/yr), which the Building Emission Rate (BER) must fall below to receive a passing grade. 

Other criteria, including maximum U values, minimizing excess solar gains, and meeting minimum building service efficiencies, must also be met.

How SBEM Calculations Work

When it comes to getting building approval, the process just got tougher. The new Part L 2013 regulations have made it even more challenging to obtain a “Pass” certificate for your building. In fact, now more than ever it’s essential that you obtain an SBEM Calculation.

There are now two stages to getting an SBEM Calculation. The first stage, the “Design Stage”, must be completed and submitted to the Building Control Officer or Approved Inspector along with your application. The second stage, the “As Built” SBEM Calculation, is required upon completion and must be provided to the Inspector prior to sign-off.

Recommendations for SBEM

Achieve Part L compliance with our SBEM Recommendations

Maximize your Part L compliance with these key recommendations:

  • Conduct SBEM during project design.
  • Exceed minimum U-Values by using high-performance materials.
  • Avoid electric heating panels and choose an efficient heating system.
  • Use passive measures for ventilation and solar gain like solar shades and coated windows.
  • Select energy-efficient LEDs for lighting throughout the construction.
  • Ensure airtightness in the building and conduct air testing.

Two Types of Simplified Building Energy Model (SBEM)

New Non-Domestic Buildings (Part L2a)

Build your new commercial property right with Part L2a of the building regulations. Ensure your non-domestic building meets its energy emission rate requirement with a cost-effective solution provided by our experienced team of accredited energy assessors. 

We customize every project, providing a bespoke solution that’s tailored to your needs. Trust us to help you save thousands of pounds while developing long-lasting relationships. 

Before starting construction, all SBEM calculations must be submitted to the building control officer. Once your new property is complete, our team can prepare the Energy Performance Certificate (EPC) using the SBEM calculation. 

We can even assist with Air Permeability Testing upon completion. Contact us to ensure your new commercial property satisfies the energy efficiency requirements.

Non-Domestic Extensions (Part L2b)

Are you planning to build an extension to an existing non-domestic or commercial building? Make sure your project is compliant with Part L1b of the building regulations by assessing it using the SBEM calculation methodology. 

While the requirements for extensions aren’t as strict as new build standards, new thermal elements must meet the correct levels to ensure proper insulation. Plus, after completion, the SAP calculation is used to prepare the Energy Performance Certificate (EPC). Start your project off on the right foot with these important regulations in mind.

What do you need to provide for an SBEM Calculation?

  • Building construction plans
  • Types of heating to be used
  • Types of lighting to be used
  • Ventilation and air conditioning
  • Use of renewable energy sources (solar PV, wind turbines, ground/air-source heating, etc.)

When is an SBEM Calculation Required?

When constructing a new building or proposing a change in use, it’s crucial to perform energy calculations. The same goes for fit-outs, refurbishments, and commercial extensions. To comply with Building Regulations Part L1B, non-domestic projects must undergo SBEM calculations. 

These produce a report certificate that shows the building’s SBEM rating. A pass means that the project meets regulations. Depending on whether it’s a new build, extension, or refurbishment, SBEM calculations and requirements differ. For a new build, calculations determine the target emission rating (TER) and building emission rating (BER). 

The BER must be equal to or lower than the TER for a passing SBEM rating on the certificate.

The 2013 Building Regulations Part L2A, introduced in April 2014, pose substantial obstacles for new commercial buildings. Compared to the 2010 edition, these regulations have undergone significant changes, including the use of a notional building to dictate carbon dioxide targets that closely align with the actual building’s size and shape. 

To provide nine percent carbon dioxide savings across new non-domestic buildings, the Part L 2013 specifications have also been reinforced.

A broader range of notional buildings has been established for top-lit, side-lit (heated only), and side-lit (heated and cooled) buildings. The notional building’s air permeability has also been subdivided by size. You can find a list of these notional buildings in Table 5 of the approved document or the National Calculation Methodology (NCM) modeling guide.

If you construct the actual building in exact accordance with the notional building specifications, it will meet the carbon dioxide targets and the limiting fabric and building services parameters. Nonetheless, developers are free to modify the requirements, as long as they achieve or surpass the same overall level of reducing carbon dioxide emissions.

What types of non-residential buildings need an SBEM Calculation?

Ensure Your Commercial Building Meets Regulations with BRUKL Compliance and SBEM Calculations. All new commercial and non-residential dwellings require a regulatory BRUKL compliance report and certificate, along with SBEM Calculations. 

Even extension projects that exceed 100m² and 25% of the original building must comply. Don’t take any chances – get the evaluations and certifications your building needs to operate legally. These non-residential buildings require an SBEM Calculation: 

  • Shopping Centres
  • Offices
  • Restaurants
  • Leisure Centres
  • Care Homes
  • Warehouses and Industrial Units

Who is qualified to conduct an SBEM Calculation?

To ensure accurate SBEM calculations, only qualified Level 4 or 5 Non-Domestic Energy Assessors should undertake the task. Additionally, to avoid extra expenses, it’s crucial to verify that they’re accredited by the right body to provide Energy Performance Certificates once the build is complete. Don’t take chances; verify credentials before proceeding.

Looking for tips on how to ace your SBEM calculation?

  • Start with the lighting systems. Highly efficient fittings and controls can make a significant impact on the calculated SBEM result, lowering CO2 emissions and improving sustainability.
  • Designing an air tightness barrier for your building is crucial for achieving a low Building Emission Rate (BER) within the SBEM Assessment. By factoring in the location and potential performance of the barrier during the design process, you can save on costs by avoiding penalties for air permeability rates exceeding 15 m3.h.m2, especially for commercial buildings under 500m2. Opt for a voluntary air tightness test instead to achieve optimal results.
  • Make sure to assess your building for compliance with Approved Document L: Volume 2 (or equivalent) early on while there is more flexibility to make recommended specification changes.

Before beginning the SBEM assessment, it’s crucial to consider key factors during the design stage for optimal results. Here are a few things to keep in mind:

  • Maximize energy efficiency with smart lighting choices.
  • Ensure top-notch insulation to prevent heat loss through walls and ceilings.
  • Choose suitable HVAC systems that match the size of the home.
  • Ensure proper heating systems are in place to heat the entire building.
  • Install effective ventilation to maintain air quality.

What occurs if my building doesn’t pass the SBEM Evaluation?

If your building doesn’t pass the first SBEM Assessment, we’ll collaborate with you to develop affordable and pragmatic specification changes. Our aim is to help you comply with the Approved Document L: Volume 2 of the Building Regulations (or relevant local laws).


Don’t risk your building plans being rejected or delayed. We at L2 Energy Consulting specialize in SBEM Calculations, and we’re here to help guide you through the entire process. Our experienced and friendly team will provide you with the best advice to ensure your plans pass with flying colors. Our fast track service is even available at no extra cost.

Get in touch now to discover how we can help you achieve a successful outcome with our SBEM know-how and expertise.

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Post written by: Sam Guest

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