SBEM Calculations

What is an SBEM

What Is SBEM?

SBEM is a tool for demonstrating the energy efficiency of non-domestic buildings, both new and old.

SBEM is the abbreviation for ‘Simplified Building Energy Model.’ It’s a government-approved method for calculating the amount of energy needed to heat, cool, ventilate, and light a non-dwelling structure.

Based on a 12-month period of ‘normal’ use, it provides a realistic representation of the building’s energy and carbon dioxide emissions, as well as its energy efficiency (or lack thereof). Offices, warehouses, retail units, restaurants, leisure centres, and retirement homes are examples of non-domestic structures.

SBEM reports

  • Ensure that the Building Emission Rate (BER) isn’t greater than the Target Emission Rate (TER).
  • Assess the fabric of the building.
  • Assess for energy efficiency, all ventilation, heating, cooling, water heating, and permanent lighting systems.
  • Set down control measures designed to reduce solar gains in summer, thereby reducing the need to install air conditioning.
  • Ensure that steps have been taken to allow the building to function energy efficiently.

There are two formats for SBEM calculations: one covers new builds (L2A); the other deals with conversion and extension work (L2B). The most important purpose of SBEM figures is to create a BRUKL (Building Regulations Part L) report which generates a brand-new EPC, or one that has recently been updated.

What do SBEM calculations do for me?

SBEM calculations are mandatory under Part L (England & Wales), Section 6 (Scotland), and Part F1 (Northern Ireland) of Building Regulations. These are all documents relating to power and fuel conservation. SBEM calculations were introduced with the 2006 UK Building Regulations.

SBEM calculations are a prerequisite for any new or updated Energy Performance Certificate (EPC) and give a property rating ranging from one to one hundred — the higher the number, the higher the efficiency. It is illegal to sell or rent out a commercial building that has no EPC.

What information goes into an SBEM?

For us to produce an SBEM report, our customer needs to provide the following information. The list is not exhaustive but it’ll give you a fair idea of what we need:

  • Floor plans
  • Elevations
  • Sections
  • Site Plans
  • Insulation type and thickness
  • U-values for all openings
  • Heating system specifications
  • Details of the method used to produce hot water
  • Lighting specifications (including lighting controls)
  • Cooling and ventilation specifications
  • Details of any renewable technologies
  • Accredited building details

It’s important not to over-simplify SBEM calculations, however. Final figures are dependent on the nature of the construction: new build, conversion, or extension. In all cases, two reports are generated — new builds require design stage and as built reports. Conversions and extensions are governed by L2B SBEM Calculations and give rise to a notional and a proposed report.

L2A SBEM New-Build Calculations

Design Stage


  • Scrutinise and pass the property’s construction details before construction starts;
  • Use specialist SBEM software to generate a TER rate and show BER compliance; then
  • Create an assessment of predicted energy use.

As Built Report

  • On completion of the project, details of the construction are assessed afresh and final calculations are added, e.g., the designated type of boiler model.
  • The EPC derives from this report.

The Calculation of L2B SBEM (extensions and conversions)

Notional Report


  • Carry out an assessment of the construction of the whole property, in addition to the proposed extension or conversion.
  • Create a benchmarked data report.
  • Use specialist SBEM software to generate a TER rate and to prove that the building is compliant with BER regulations.

Proposed Report


  • Use benchmark data for existing components. Actual performance data are used for new or upgraded components.
  • Use specialist SBEM software to generate a TER rate and to prove that the building is compliant with BER regulations.
  • Pass the property only when its performance values are lower than benchmarked standards.
  • Also check that overall BER measurements are lower in the proposed report than in the notional report.
  • We will replace the existing EPC with a new EPC, where SBEM calculations demonstrate that all building performance values are lower in the proposed report than in the notional report.

Scheduling SBEM Calculations

Two SBEM assessments are required: one at the beginning of the building project, and another at the end. We can produce an SBEM calculation at Design and As-Built Stages.

Design Stage SBEM Calculations

Design Stage SBEM Calculations must be produced before building work starts, so you should submit an SBEM report and Building Control/ Warrant Application to a Building Control Body or Verifier (Scotland) without delay or building work cannot start.

As-Built Stage SBEM Calculation

On completion, As-Built SBEM Calculations are needed to ensure that the finished building remains compliant.

What exactly does an SBEM Calculation offer?

Commercial SBEM calculations indicate the carbon footprint of the surveyed building as required under Building Regulations Part L. These calculations demonstrate energy costs and carbon emissions resulting from the proposed design.

Changes are often made as the project progresses, in consultation with architects, developers, or customers, to make sure that the building is always in full compliance with current regulations. We recommend that you engage an official accredited consultant before committing to your final design.

Do I also need an EPC?

The short answer is yes. Post-construction — once all works have been completed according to SBEM specifications — an Energy Performance Certificate (EPC) is created using SBEM figures. If you have engaged us to carry your SBEM calculations, we will supply your EPC free of charge.

You can rely on us for exceptional service:

  • We can carry out SBEM calculations for projects of any size.
  • We will review all specifications and plans.
  • We will offer recommendations, and make sure we meet your deadlines.
  • We will supply your Energy Performance Certificates (EPCs) free of charge.
  • Our staff are all accredited experts, highly experienced in their field.
  • We can offer cost-effective neutral advice on how to increase the energy efficiency of your property.
  • We take pride in having a fully trained team of professionals, dedicated to helping you meet your deadlines. We will keep you up to speed throughout the process. If it suits you, we are always willing to engage directly with your Building Control Office or Design Team.
  • Our assessors are CIBSE qualified to Level 5. This means we are qualified to carry out SBEM calculations on the most complex projects — those which incorporate, for example, atriums and complicated ventilation systems.

Dynamic Simulation Modelling

DSM software is designed to calculate data for new build commercial properties. It is also highly accurate and takes account of other external factors capable of impacting on energy consumption.

DSM software comes into play with large scale complex constructions such as airports, shopping centres, or sky-scrapers. But the software can prove very useful for those customers who want a more detailed analysis for their intended non-domestic project.

In commercial buildings we use Dynamic Simulation Modelling (DSM) to provide a much more detailed and accurate assessment using a 3D model of your building. This model enables us to analyse:

  • Thermal Performance / Construction
  • Renewables and Technologies
  • Energy usage
  • CO2 Emissions
  • Overheating
  • Daylight / Sunlight Assessment
  • Ventilation / Airflow
  • Occupant Comfort
  • BREEAM / LEED Performance

Briary Energy typically use DSM for large developments such as hotels and office blocks.

Briary Energy DSM
Rendered DSM using DesignBuilder Software

Frequently Asked Questions

SBEM is the acronym for 'Simplified Building Energy Model'. The methodology that has been approved by government calculates the energy that’s needed to light, ventilate, heat, or cool a building not used as a dwelling. SBEM calcs demonstrate the energy performance of both new and existing commercial (i.e., non-residential) buildings.

A Simplified Building Energy Model (SBEM) assessment is a government-approved methodology used throughout the UK in order to calculate how energy-efficient commercial properties are. An SBEM report takes into account the size, geometry, orientation, construction, and systems of a building to calculate the amount of energy it uses monthly and its carbon emissions.

The Building Research Establishment (BRE) has developed SBEM as a software tool to analyse and calculate non-domestic building energy performance. SBEM is intended for use in commercial, non-domestic buildings and supports the National Calculation Methodology (NCM), the Energy Performance of Buildings Directive (EPBD), and the Green Deal.

BRUKL output documents are those that calculate a non-domestic building energy rating. The term BRUKL stands for Building Regulations UK, Part L and is often used interchangeably with ‘SBEM (Simplified Building Energy Model) report’. The SBEM is the most common methodology used to produce a BRUKL output document.

A Building Regulation UK Part L (BRUKL) report lays out the energy usage and fuel conservation methods used in a non-domestic building. The document reports on the likely emissions of a building and is used throughout the building process to monitor the extent to which the property complies with the relevant regulations.

Dynamic Simulation Modelling (DSM) refers to a software package that has been designed to predict the energy performance of larger and/ or more complex commercial buildings which are required by the relevant regulations to hold Level 5 EPCs. A few examples of buildings that need Level 5 EPCs are shopping centres, skyscrapers, and airport terminals.

An EPC assessment is the process carried out to produce an Energy Performance Certificate (EPC) on a building. The EPC assessment calculates how energy-efficient a property is and how much it will cost to heat and light it on a scale of 1-100. Properties are graded into bands A to G, where A is most efficient, G is least.

An Energy Performance Certificate (EPC) is drawn up after an SBEM assessment has taken place. The EPC states the energy-efficiency rating of a property and is a legal requirement for any sale or rental of a non-dwelling. Building Control will also require an EPC before they will sign off on a property.

There is no pass or fail with an EPC, but the document informs potential buyers and tenants of the energy efficiency of a property. A very poor score may adversely affect your chances of selling or leasing out your building. Your EPC grading is based on data drawn from a commercial building energy assessment such as an SBEM.

An EPC is valid for a period of ten years and within this period, can be utilised any time a property is sold or leased out. After the ten-year period is up, a new commercial building energy calculation must be carried out and an EPC produced if the building is to be marketed for sale or rented out thereafter.