A practical guide to the Simplified Building Energy Model used for warehouses, factories, offices, retail units and all non-domestic buildings in England and Wales.
SBEM (Simplified Building Energy Model) is the government-approved software tool used to calculate the energy performance of non-domestic buildings in England and Wales. Developed by BRE (Building Research Establishment) on behalf of the Department for Energy Security and Net Zero, SBEM produces the standardised energy ratings that appear on commercial Energy Performance Certificates.
When you receive a non-domestic EPC for your warehouse, factory, office or retail premises, the rating has been calculated using SBEM methodology. The software models the building as a series of zones, each with defined construction, heating, cooling, lighting and ventilation characteristics. It then calculates annual energy consumption and carbon dioxide emissions, comparing these against a notional reference building of the same size and shape to produce the familiar A-to-G rating scale.
Unlike domestic SAP assessments which focus on houses and flats, SBEM handles the full complexity of commercial buildings. A single warehouse with office annexe, loading bays, staff areas and mezzanine storage presents multiple zones with different occupancy patterns, heating requirements and lighting specifications. SBEM models each zone independently before calculating the whole-building performance.
Wall construction, roof insulation, floor type, glazing specifications, air permeability and thermal bridging. These define how well the building retains heat.
Boilers, radiant panels, warm air heaters, heat pumps, underfloor heating and their associated controls. Efficiency and fuel type directly affect ratings.
Lamp types (LED, fluorescent, sodium), lighting density, occupancy sensing, daylight dimming and manual switching. Lighting often dominates warehouse energy use.
Natural ventilation, mechanical supply and extract, heat recovery units, air handling systems and local extraction for industrial processes.
Solar PV panels, biomass boilers, heat pumps, solar thermal systems and wind turbines. These reduce the building's net energy consumption.
Domestic hot water systems for washrooms, kitchens and staff facilities. System type, insulation and controls all contribute to the assessment.
Industrial buildings present particular challenges for SBEM modelling. A typical warehouse or factory may feature high ceilings exceeding 10 metres, large roller shutter doors, minimal insulation in older structures, and heating systems designed for intermittent use rather than continuous comfort.
Our assessors have extensive experience modelling these building types across Devon, Cornwall, Somerset and Dorset. Common industrial SBEM scenarios include:
It is worth noting that SBEM assesses the building itself, not the processes carried out inside it. Manufacturing equipment energy use, material handling systems and production-line power consumption are excluded from the calculation. The EPC rating reflects the building envelope, fixed building services (heating, cooling, lighting, ventilation) and any renewable energy generation.
Our assessor visits your property to measure dimensions, inspect construction details, record heating and lighting systems, check ventilation arrangements, and photograph key features. For a standard industrial unit, this takes 1-3 hours.
Survey data is entered into the approved SBEM software. The building is divided into thermal zones based on activity type, heating provision and construction. Each zone is defined with its specific characteristics.
SBEM calculates the annual energy demand for heating, cooling, lighting, ventilation and hot water. It then compares your building against a notional reference building of identical geometry but with standardised systems and construction.
The comparison produces a Building Emission Rate (BER) expressed as kgCO2/m2/year. This is converted to the A-to-G rating scale and the EPC is lodged on the national register. You receive the certificate with detailed recommendations for improvement.
One of the practical benefits of SBEM modelling is the ability to test proposed improvements before committing expenditure. Our assessors can model the impact of various upgrades on your building's energy rating, helping you make informed decisions about which measures offer the best value.
Common improvements that show significant benefit in SBEM calculations for industrial buildings include:
Replacing high-bay sodium or metal halide lighting with LED equivalents typically improves SBEM ratings by 10-20 points. For warehouses where lighting is the dominant energy use, this can shift a rating from F to D.
Adding insulation above existing industrial roofing reduces heat loss significantly. Combined with improved airtightness, this can improve ratings by 5-15 points depending on existing conditions.
Adding time and temperature controls, optimum start/stop and zone control to existing heating systems demonstrates better management of energy use in the SBEM model.
Large industrial roof areas are ideal for solar PV. The generated electricity offsets grid consumption in the SBEM calculation, improving the overall rating. Panels can also generate income through export.
SBEM stands for Simplified Building Energy Model. It is the government-approved calculation methodology used to assess the energy performance of non-domestic buildings in England and Wales, including offices, retail units, warehouses, factories, schools, hotels and all other commercial premises.
An SBEM calculation is required for producing Energy Performance Certificates (EPCs) for non-domestic buildings when selling, letting or constructing the property. It is also needed for Building Regulations Part L compliance on new-build commercial projects and for demonstrating MEES compliance on rental properties.
SBEM is used for non-domestic (commercial) buildings, while SAP (Standard Assessment Procedure) is used for domestic dwellings. SBEM handles more complex building types with multiple zones, varying occupancy patterns, and diverse heating and cooling systems. SAP is specifically designed for houses and flats.
The site survey typically takes 1-4 hours depending on building size and complexity. The SBEM modelling and certificate production usually takes 5-7 working days after the survey. Larger or more complex buildings such as multi-zone factories or buildings with mixed-use areas may take longer to model accurately.
SBEM calculations for EPCs must be carried out by accredited Non-Domestic Energy Assessors (NDEAs). For Building Regulations Part L compliance, calculations can be performed by qualified energy consultants using approved SBEM software. Our assessors hold Elmhurst accreditation for non-domestic energy assessment.
Yes. SBEM modelling allows assessors to test the impact of proposed improvements before committing to expenditure. We can model scenarios such as LED lighting upgrades, heating system replacements, insulation improvements and renewable energy installations to show which measures offer the best return on investment for your specific building.
Warehouse, factory and workshop assessments
Minimum energy efficiency standards for landlords
Distribution centres and storage facilities
Manufacturing plants and production facilities
Light industrial units and trade premises
General guide to Energy Performance Certificates
Professional SBEM calculations for commercial and industrial buildings across Devon, Cornwall, Somerset and Dorset. Accredited assessors with fast turnaround.
For SBEM-based commercial advice engagements, we apply a systematic two-stage process: each candidate improvement measure is first modelled in isolation and ranked across five criteria (EPC points, energy saving, CO2, cost saving, payback), then the top-ranked measures are grouped into three cumulative implementation Rafts — priority, Band C target, and deep retrofit. This is how the NDEAR (Non-Domestic Energy Advice Report) reports we produce turn a single EPC into three costed, modelled pathways.
Read the full methodology