What is the difference between SBEM and SAP?

SBEM assesses non-domestic buildings against their actual use class, floor zoning and installed services, while SAP and RdSAP assess dwellings. They are separate methodologies producing separate certificate types, and a mixed-use building can need both.

How do I know what assessment level my building needs?

It depends on the complexity of the heating, cooling and ventilation systems installed, not the floor area alone. A simple shop with basic heating typically needs level 3, while a building with air conditioning or complex controls needs level 4 or 5.

Can I still let an F or G rated commercial unit?

Only if a valid MEES exemption has been registered on the PRS Exemptions Register; otherwise granting a new lease on a sub-E rated commercial property is a breach of the regulations and can carry financial penalties.

How long does a commercial EPC last?

Ten years from the date of lodgement, the same validity period as a domestic EPC, unless the building undergoes significant changes that make an earlier reassessment sensible.

Does a landlord need a new commercial EPC for every new tenant?

Not necessarily. An existing valid EPC (within its ten-year validity) can generally be used for a new letting provided it accurately reflects the building; a new assessment is only required if none exists or the current one has expired.

Are there exemptions from needing a commercial EPC at all?

Yes, certain building types and short-term lettings are exempt from the requirement, including some listed buildings where specific alterations would unacceptably alter their character. These are narrow exemptions rather than a general opt-out.

Guide · guides

Commercial EPCs explained: SBEM, levels 3 to 5 and MEES for landlords

Non-domestic EPCs are built on a different methodology to residential ones, assessed at different levels of complexity, and carry their own minimum standard for lettings.

13 min readBy Nabhan Islam Reviewed by Awais Sarwar, MSc Updated 6 Sept 2026

Commercial EPCs explained: SBEM, levels 3 to 5 and MEES for landlords

The short answer

Commercial EPCs are underpinned by SBEM (Simplified Building Energy Model), the government-approved methodology for non-domestic buildings, which models a property's energy use against its actual services, fabric and use class. Assessments are carried out at levels 3, 4 or 5 depending on the complexity of the building's heating, cooling and ventilation systems, with more complex buildings requiring a more experienced accredited assessor. Commercial landlords letting property in England and Wales are also subject to the Minimum Energy Efficiency Standards (MEES), which currently require a minimum EPC band of E before a property can lawfully be let, subject to specific exemptions.

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Methodology

SBEM

Simplified Building Energy Model

Assessor levels

3, 4 and 5

Scaled to building services complexity

MEES minimum

Band E

For lettings, subject to exemptions

Commercial EPC cost

From £150

Depends on size, use class and complexity

What SBEM actually models

SBEM stands for Simplified Building Energy Model, and it is the calculation engine behind the vast majority of non-domestic EPCs. Rather than the age-band assumptions used in RdSAP for homes, SBEM works from the building's actual use classification, floor area, construction and installed services — heating, cooling, ventilation, lighting and hot water — to model annual energy consumption and carbon emissions, which are then converted to the familiar A-G band used on the certificate.

SBEM inputs include zoned floor areas by activity type, since a warehouse, office and retail unit have very different expected energy profiles.
Building fabric performance — walls, roof, glazing — is assessed from available construction information and, where necessary, industry-standard defaults.
HVAC system type and controls are recorded in detail, since these typically dominate energy use in commercial buildings.
Lighting type, control strategy and daylighting are all factored into the model.
Dynamic Simulation Modelling is used instead of SBEM for a small number of complex building types where SBEM's simplified approach is not considered suitable.

Assessment levels 3, 4 and 5 explained

Non-domestic energy assessors are accredited at different levels, and the level required for a given building depends on the complexity of its services rather than simply its size. A small shop with basic heating and no air conditioning needs a different level of accreditation to a large office with mechanical ventilation, chillers and building management system controls, and using an assessor accredited at the wrong level for the building can result in an invalid certificate.

Level	Typical building type	Services complexity
Level 3	Small shops, simple offices, warehouses	Basic heating, natural ventilation, no air conditioning
Level 4	Larger offices, retail units	Air conditioning and/or mechanical ventilation systems
Level 5	Complex mixed-services buildings	Combined heating, cooling, complex controls or building management systems

Accreditation levels required for non-domestic EPC assessors scale with the building's services, not its footprint alone.

When a commercial EPC is legally required

The same core trigger events apply to non-domestic buildings as to homes: an EPC is needed when a building is constructed, sold or let, and it must be made available to prospective buyers or tenants at the point of marketing rather than produced only once a deal is agreed. This applies to a single retail unit and a large multi-let office equally, though the assessment level and cost will differ substantially between them.

Construction of a new commercial building, generated from the as-built specification.
Sale of a commercial property, required for marketing rather than only at completion.
Letting of the whole or part of a commercial building to a new tenant.
Certain refurbishments that trigger a Part L compliance requirement can also require an updated EPC.

The buildings behind this advice

MEES: the minimum band E requirement

Minimum Energy Efficiency Standards apply to commercial lettings in England and Wales, and currently prevent a landlord from granting a new lease, or continuing certain existing leases, on a building rated F or G unless a valid exemption has been registered. The rule is aimed squarely at improving the poorest-performing stock in the private rented sector, and enforcement sits with local authorities (usually trading standards) rather than being self-policing.

New leases on F or G rated commercial property are generally prohibited without a registered exemption.
Exemptions include cases where required improvements would not pay back within a set period, or where third-party consent for works cannot reasonably be obtained.
Exemptions must be formally registered on the PRS Exemptions Register and are time-limited, typically requiring reassessment.
Non-compliance carries financial penalties, and details of breaches can be published by enforcing authorities.

Improving a poorly rated commercial building

Unlike domestic EPCs, where recommendations tend toward insulation and glazing, commercial recommendations more often centre on controls, lighting and HVAC efficiency, because these dominate energy use in most non-domestic buildings. The relative cost-effectiveness of measures also varies far more by use class than it does for homes, since a warehouse and an air-conditioned office have almost nothing in common in terms of where their energy actually goes.

Upgrading lighting to LED with occupancy or daylight-linked controls, often the single most cost-effective measure.
Improving heating and cooling controls, including zoning and time controls rather than whole-building settings.
Draught-proofing and improving glazing where thermal performance is genuinely poor rather than merely dated.
Upgrading or replacing inefficient HVAC plant nearing the end of its service life.
Adding roof or cavity insulation where the building fabric allows it cost-effectively.

Mixed-use and multi-let buildings

Buildings that combine residential and commercial space, or that are split between multiple tenants, are one of the more common sources of confusion. Generally, each self-contained unit needs its own EPC appropriate to its use — a flat above a shop needs a domestic EPC for the flat and a commercial EPC for the retail unit — rather than a single certificate covering the whole building, though there are specific exemptions for certain small or short-term lettings.

Self-contained residential units above or alongside commercial space generally need their own domestic EPC.
Common parts serving multiple commercial tenants are usually not separately EPC-rated in the same way as individual lettable units.
Landlords of multi-let commercial buildings typically need a certificate for each unit marketed or let separately.
Serviced offices and similar flexible-use spaces need careful assessment of which exemptions, if any, apply.

Getting a commercial EPC done properly

Because assessment level, floor area and use class all affect both cost and the eventual result, it is worth briefing whoever is commissioning the certificate with an accurate description of the building's services before a quote is given, rather than after a site visit reveals a level 4 or 5 building was booked in as level 3. This avoids delays and ensures the assessor attending is correctly accredited for what they find.

Provide an accurate description of heating, cooling and ventilation systems when requesting a quote.
Have building services drawings or a specification available if the building has been altered since construction.
Flag any recent refurbishment, plant replacement or extension that may affect the assessment.
Confirm the intended use of the certificate — sale, letting, or MEES exemption evidence — since this can affect timing.

Commercial EPCs and SBEM calculations, from £150

We cover levels 3 to 5 across London and the Home Counties, including MEES compliance checks before new lettings.

Written by

Nabhan Islam

Head of Marketing & Commercial Lead

Reviewed by

Awais Sarwar, MSc

Accredited Energy Assessor — Accredited domestic and commercial energy assessor, listed on the EPC Register

13 min readLast reviewed 6 September 2026Facts verified 6 September 2026 Checked quarterly

Sources

The Energy Performance of Buildings (England and Wales) Regulations 2012 — legislation.gov.uk
Find an energy certificate — GOV.UK
Non-domestic private rented property: minimum energy efficiency standard — landlord guidance — GOV.UK
Approved Document L: conservation of fuel and power — GOV.UK

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