Commercial EPC Frequently Asked Questions

SBEM stands for Simplified Building Energy Model. It's the government-approved methodology used to calculate the energy performance of non-domestic buildings. The assessor collects data about the building, and this data is entered into SBEM-approved software that calculates the energy rating. The assessor does not make subjective judgements — the rating is produced by the software based on the data provided.

There are different levels of NDEA qualification corresponding to different building complexities. A Level 3 assessor can survey most standard commercial buildings. More complex buildings — such as those with advanced HVAC systems — may require a Level 4 or Level 5 assessor. We'll confirm the appropriate level when you book and ensure a suitably qualified assessor is assigned.

Yes, and we encourage it. If you have specifications for the building's construction (e.g., U-values, glazing specifications), HVAC system details (make, model, efficiency ratings), or lighting design information, providing these in advance or making them available on the day can help us use actual rather than default values, which often produces a more favourable rating.

Where elements of the building fabric or its systems can't be visually inspected — for example, cavity wall insulation or concealed services — the SBEM methodology uses default values. These defaults tend to be conservative, so the rating may be slightly worse than if the actual specifications were known. This is another reason why providing documentation is beneficial.

No. Our commercial assessors are directly employed by us. They are trained to our standards, their work is quality-checked, and they are supported by our in-house technical team who carry out the SBEM modelling for complex buildings.

The Minimum Energy Efficiency Standards (MEES) make it unlawful for landlords to let a commercial property with an EPC rating of F or G, unless a valid exemption is registered. Since April 2023, this applies to all commercial tenancies — not just new leases.

Penalties are based on the rateable value of the property and the duration of the breach, up to a maximum of £150,000 for commercial properties.

Contact us for a MEES consultation. We'll assess your building, advise on the most cost-effective improvements to reach at least an E rating, and if appropriate, help you explore whether an exemption applies to your situation.

There has been ongoing policy discussion about raising the minimum standard to a C rating for commercial properties. While no firm date or legislation has been confirmed, it's worth understanding where your property sits and planning ahead. We can advise on the implications for your portfolio.

Possibly. The MEES regulations include several exemption categories — including where improvements can't pay for themselves within seven years, where wall insulation would damage the building, where third-party consent is refused, or where improvements would reduce the property value by more than 5%. Exemptions are valid for five years and must be registered. We can assess whether your building qualifies.

A Display Energy Certificate (DEC) shows the actual energy performance of a public building based on its real energy consumption over 12 months. Unlike an EPC, which is theoretical, a DEC reflects how the building is actually used and operated.

You need a DEC if your building is occupied by a public authority or institution providing a public service, is over 250m² in floor area, and is frequently visited by the public. This includes council offices, libraries, schools, leisure centres, health centres, and similar.

For buildings over 1,000m², annually. For buildings between 250m² and 1,000m², every 10 years.

It might. If the building is being sold or let as well as being a public building, you'll need both. They measure different things — a DEC reflects actual energy use, while an EPC reflects the building's theoretical performance.

They're the same thing. "Commercial EPC" is the everyday term used by most people. "Non-domestic EPC" — or "non-domestic energy performance certificate" — is the official terminology used in the legislation and by the government's EPC register. Both refer to the energy assessment required for any building that isn't a dwelling. You may also hear it called a "business EPC" or simply an "EPC for commercial property."

SBEM (Simplified Building Energy Model) is the government-approved calculation methodology for producing commercial EPC ratings. iSBEM is the free, basic software interface that most assessors use to enter SBEM data. It works, but it's limited — particularly for complex buildings with unusual geometry, mixed HVAC systems, or multiple zones. DesignBuilder is a professional-grade 3D modelling platform that also runs the SBEM calculation but produces more accurate results by building a true three-dimensional model of the building. We use DesignBuilder. The difference in accuracy can be significant, especially for borderline MEES ratings.

Non-domestic buildings are categorised by complexity for assessment purposes. Level 3 covers simple commercial buildings like small shops and restaurants with basic heating. Level 4 covers more complex buildings such as air-conditioned offices, larger retail premises, and new builds. Level 5 covers the most complex buildings — large offices, hospitals, shopping centres — requiring Dynamic Simulation Modelling (DSM). Our assessors are qualified to Level 4, and our technical team's use of DesignBuilder means we produce Level 4 assessments with an accuracy that approaches Level 5 — particularly valuable for MEES-critical buildings.

The cost depends on the building's size, complexity, and type. A small shop or retail unit will cost less than a multi-floor air-conditioned office. We provide fixed quotes after understanding your property — no hidden fees or surprises on the day. Unlike many providers, our price includes the full SBEM modelling by our dedicated technical team using DesignBuilder, not a quick iSBEM assessment by the same person who visited the site. For an accurate quote, call us on 020 8166 5699 or complete our online form.

Yes, and this is one of the key advantages of our DesignBuilder-based approach. Because we build a full 3D model of your building, we can test improvement scenarios within the model — for example, switching from fluorescent to LED lighting, upgrading heating controls, adding insulation, or improving glazing — and show you the expected impact on your rating before you commit to spending any money. This is particularly valuable for MEES compliance, where you need to know the most cost-effective route to an acceptable rating.

This is a common source of confusion. The EPC regulations technically do not require a new certificate on lease renewal alone. However, the MEES regulations make it unlawful to continue letting a property rated F or G — even on existing, mid-term tenancies. The government's MEES guidance recommends obtaining a current EPC on renewal to demonstrate compliance. In practice, many solicitors now insist on a valid EPC as part of lease renewal due diligence.

Generally yes, if the warehouse is being sold or let and has any form of fixed heating or the potential for fixed heating. Unheated warehouses used purely for storage may be exempt, but this exemption is narrower than many people think. If in doubt, it's usually simpler and cheaper to get the EPC done than to argue the exemption — particularly since warehouse EPCs are often straightforward and relatively inexpensive.

If the flat has its own separate entrance, you'll need a commercial EPC for the shop and a separate domestic EPC for the flat. If access to the flat is only through the shop (no separate entrance), one commercial EPC can cover the whole building. Through our main company, we can arrange both commercial and domestic assessments in one visit.

The current minimum EPC rating for letting any commercial property in England and Wales is E. Properties rated F or G cannot legally be leased. The government has proposed raising the minimum to C by 2027 and B by 2030 under tightened MEES regulations. If you're a commercial landlord with a property rated D or below, it's worth getting advice now rather than waiting for the deadline. Our MEES consultation service can help.