The Importance of SBEM in Non-Domestic Building Compliance

Sbem commercial building

What Is SBEM

SBEM stands for Simplified Building Energy Model.

SBEM calculates the monthly energy use and carbon emissions of non-domestic buildings based on factors such as size, orientation, construction, geometry, and systems.

The purpose of the SBEM assessment is to establish the energy performance of buildings early in the design process and demonstrate compliance with UK building regulations concerning the conservation of fuel and power.

In practice, there are two reasons for SBEM calculations for compliance, for new building constructions and for extensions and conversions.

SBEM calculations are crucial for sustainable construction as they help in designing buildings that are energy-efficient and meet the increasingly stringent energy standards.

By integrating SBEM calculations early in the design process, developers and builders can reduce costs and have more flexibility in choosing materials and energy-efficient systems

NDEA at computer

Stages Of SBEM Assessments

SBEM calculations are crucial during the ‘as design’ stage as they can predict potential compliance challenges with Building Regulations.

Design stage SBEM, known as ‘As Design’, must be completed before construction begins to forecast any potential barriers to Building Regulations compliance.

Early participation of the SBEM assessor in the design team is beneficial to pinpoint issues that could hinder compliance, thus mitigating costs related to significant design adjustments.

An ‘As Built’ SBEM calculation is performed after construction finishes, incorporating any available air tightness test results to ensure regulatory compliance.

The ‘As Built’ SBEM calculation is a step for building control to validate the project and for issuing the building’s Energy Performance Certificate (EPC).

SBEM Calculation Process

SBEM calculations are mandatory for all new non-domestic buildings with a heated or cooled environment and an internal floor area exceeding 50m2, as per Part L Volume 2 of the Building Regulations.

Detailed building information including floorplans, elevations, sections, and site plans are required to produce SBEM calculations.

For a comprehensive SBEM assessment, input data must include specifications of heating, ventilation, cooling, and lighting systems, including controls and efficiencies.

Construction details such as the type and thickness of insulation and U-values of openings must be provided to assess the building’s thermal efficiency

For conducting SBEM assessments, tools such as iSBEM, DesignBuilder, IES, and TAS are commonly used.

Assessor new build plans

Compliance with Building Regulations

To achieve SBEM compliance with Part L of the building regulations, The Building Emission Rate (BER) calculated by SBEM must be less than the Target Emission Rate (TER) the second target the Building Primary Energy Rating (BPER) must also be less than the Target Primary Energy Rating (TPER).

Energy efficiency can be improved through various measures such as retrofitting HVAC systems, increasing building airtightness, avoiding electric panel heaters, incorporating natural ventilation, implementing a low wattage lighting design, and introducing daylight and motion sensing controls.

Continued efforts to improve energy performance can include ensuring high-efficiency ventilation systems, minimising heat loss from hot water storage, constructing buildings with low U-values, performing regular HVAC maintenance, proper insulation, employee energy-saving practices education, and investing in smart building technology.

To ensure smooth SBEM compliance and minimise potential issues, it is advised to engage in collaboration, thorough planning, and regular assessments with certified energy assessors such as ourselves throughout the project’s lifecycle.

The final output report from SBEM that shows compliance is called the BRUKL report.

What is a BRUKL report?

BRUKL stands for “Building Regulations UK Part L.” It is a reference to Part L of the Building Regulations in the United Kingdom, which deals with the conservation of fuel and power in buildings. The term “BRUKL” is its most commonly used term.

BRUKL reports typically include detailed information about the building’s design, construction, and energy performance. They often incorporate data on the building’s envelope (walls, roofs, floors, windows), heating, cooling, ventilation systems, lighting, and other relevant features. These reports are used to calculate the building’s energy performance and ensure that it complies with the energy efficiency standards set forth in Part L of the Building Regulations.

A BRUKL report has to be provided to the local building control body prior to commencement of any building work and is there to demonstrate that the proposed building will be compliant with Part L of the building regulations.

Brukl report

Difference between SBEM and SAP


SBEM calculations are used to assess the energy performance of non-residential buildings while SAP calculations are designated for residential buildings.

SBEM calculations are necessary for meeting building regulations, whereas SAP calculations cater to the energy assessment of domestic buildings.

Buildings with mixed-use, where they contain both dwellings and non-dwellings, necessitate the use of SBEM calculations for the commercial areas and SAP calculations for the residential parts.

SBEM calculations are a legal requirement for producing Energy Performance Certificates for commercial properties, and they are mandatory when renting or selling. 

SAP calculations are a legal requirement for demonstrating building regulation compliance for residential properties and in cases where the property is to be sold or rented, an EPC also must be produced.
Different qualifications are required to produce either report.

To carry out SBEM calculations, the assessor must be a qualified non-domestic energy assessor (NDEA). To carry out SAP calculations, the assessor must be a qualified On Construction Domestic Energy Assessor (OCDEA).
Our in house team can provide calculations for either SBEM or SAP, so get in touch for further assistance.

Achieving net zero carbon in new buildings

Both SBEM and SAP are calculation tools that can measure CO2 emissions in buildings as well as help us to design more efficient buildings.

“Net zero” in the context of a new building refers to the goal of achieving a balance between the amount of energy the building consumes and the amount of renewable energy it generates on-site, resulting in a net energy consumption of zero over the course of a year.

In other words, a net-zero energy building produces as much energy as it consumes, typically through the use of renewable energy sources, such as solar panels. Achieving net-zero status is a significant sustainability milestone and can significantly reduce a building’s environmental impact.

It is easier to achieve net zero carbon on a new build, as smarter designs can be implemented from a blank canvass.

Many local authorities are aiming for net zero in their local areas. Where net zero cannot be achieved, the local authority can charge the developer a carbon levy. This carbon levy can be used to fund other project in the local area that will reduce CO2 emissions.

We’ll look at some building design features that help buildings get nearer to zero carbon.

7  Main Factors in Creating Energy-Efficient New Buildings

1. Building Fabric Design

A well-designed building envelope, with high-quality insulation, airtightness, and advanced glazing, can minimise heat loss or gain, reducing the need for heating and cooling.

The 2021 building regulations Part L volume 2 (buildings other than dwellings) states that as a minimum, the following fabric u-values in W/(m2K) need to be achieved:

  • Walls: 0.26
  • Flat Roofs: 0.18
  • Pitched roof: 0.16
  • Floors: 0.18
  • Windows: 1.6
  • Air permeability (for new buildings): 8.0m3/(h.m2)@ 50Pa

To achieve zero carbon, u-values lower than these will need to be reached.

2. Passive solar design
Incorporating passive solar principles, such as optimising building orientation and using thermal mass, can help regulate indoor temperatures naturally, again reducing the reliance on mechanical heating and cooling systems.

3. Energy-efficient HVAC systems
Employing energy-efficient heating, ventilation, and air conditioning (HVAC) systems, along with advanced controls and zoning, can significantly reduce energy consumption for climate control.

4. Building automation and controls
Implementing smart building technologies and energy management systems can better manage energy use by monitoring and controlling various building systems, including lighting, HVAC, and ventilation.

5. Energy-efficient lighting
Utilising LED lighting and daylighting strategies, such as skylights or large windows, can reduce electricity consumption for lighting.

6. Renewable energy sources
Installing renewable energy systems like solar panels or wind turbines on-site allows the building to generate its own electricity and potentially achieve net-zero energy consumption.

7. Commissioning and regular maintenance

Ongoing commissioning and maintenance of building systems ensure they operate at peak efficiency, helping to sustain net-zero performance over time.

Zero Carbon – The 4 Biggest Challenges and Barriers

Net zero carbon challenges

1. High Initial Costs

Implementing zero-carbon technologies and sustainable building practices often comes with higher upfront costs compared to conventional construction. This can be a significant barrier for developers and investors who may prioritise short-term financial returns.

2. Lack of awareness and knowledge

Many architects, engineers, and builders may not be fully aware of the latest green building technologies and may not have the expertise to design and construct zero-carbon buildings. Education and training are essential to overcome this barrier.

3. Technical challenges

Integrating and optimising various zero-carbon technologies, such as advanced HVAC systems, energy-efficient lighting, and renewable energy generation, can be technically complex. Ensuring these systems work seamlessly together is crucial for achieving zero carbon.

4. Financial incentives and market demand

Developers may be hesitant to invest in zero-carbon technologies without financial incentives or a clear demand from tenants and buyers for sustainable buildings. Government incentives and consumer preferences can help drive adoption.


In conclusion, SBEM, or Simplified Building Energy Model, plays a vital role in the construction and compliance of non-domestic buildings in the UK.

It enables early assessment of a building’s energy performance, ensuring it aligns with stringent regulations aimed at conserving fuel and power.

Moving toward a sustainable future, SBEM, along with SAP, can help in achieving net-zero energy consumption in new buildings.

In summary, SBEM and its related processes are indispensable tools in the pursuit of energy-efficient and sustainable non-domestic buildings, contributing to a greener and more sustainable future in the construction industry.

Need SBEM or SAP For Your Project

Call our commercial team on 0203 576 2544


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Rickie Dickson

Written by Rickie Dickson

Rickie Dickson is an experienced and qualified domestic and non domestic energy assessor. He helps homeowners and businesses in all matters relating to energy efficiency, from meeting building regulations compliance to improving a property’s energy rating score.