Commercial EPC Assessor for Non Domestic Buildings
If you are selling, letting or completing a new build, a commercial Energy Performance Certificate (EPC) is usually required. KJ Tait carries out EPC assessment and lodgement for non domestic buildings across England, Scotland and Wales. Our site surveys focus on the evidence that affects the rating so the certificate reflects how the building is configured at the time of assessment. If you send the building address, use type, approximate floor area and target date, we can confirm scope and provide a fee proposal.
- Non domestic only. We assess and lodge EPCs for commercial property, not dwellings.
- Coverage: England, Scotland and Wales. We do not provide EPC services in Northern Ireland.
- England and Wales EPCs are valid for 10 years. In Scotland, EPC reform regulations are intended to take effect from 31 October 2026 and include a reduction in validity to 5 years. Read our Scotland EPC changes update .
- EPCs are lodged on the official national register for the relevant jurisdiction.
- EPCs are commonly needed for sale, letting and completion of new build works.
What we do
KJ Tait provides commercial EPC assessment and lodgement for non domestic buildings across England, Scotland and Wales. We complete a site survey, apply the relevant approved methodology and lodge the EPC on the appropriate national register.
You receive the lodged certificate and a short note of the key inputs and assumptions used. If evidence is missing, we set out what matters, what is still unknown and what impact it may have on the rating.
If the EPC is being used to manage Minimum Energy Efficiency Standards (MEES) risk or an EPC B target, see our EPC B Pathway service .
EPC levels (3, 4 and 5)
Non domestic EPC assessments are commonly grouped into Levels 3, 4 and 5. The level refers to the complexity of the building and the assessment method, not the A to G rating itself.
Levels 3 and 4 are typically produced using the Simplified Building Energy Model (SBEM) methodology. Level 5 assessments use Dynamic Simulation Modelling (DSM), which creates a full 3D thermal model and simulates performance over time.
Our approach: KJ Tait undertakes Level 5 DSM EPC assessments using IES VE. We use the same modelling software as our building services design work. Any type of building can be completed in our software.
Level 5 DSM is required for some complex buildings where simplified methods cannot represent key features and controls accurately.
DSM can also be used for simpler buildings. For this reason, we can assess any non domestic building as Level 5. Where a building would normally be assessed at Level 3 or 4, we explain the assumptions used and the evidence that would materially affect confidence in the result.
When an EPC is required
EPCs are typically required when a building is sold, let to a new tenant or newly constructed. Some projects also trigger EPC requirements where a building is altered for separate occupation and the scope of fixed building services changes.
Requirements and documentation vary by jurisdiction. In Scotland, commercial sales and letting adverts must also include the EPC rating.
Practical point: If you have a marketing date, commission the EPC early. Most delays relate to access, multi let coordination and incomplete O&M information.
Scotland EPC changes from 31 October 2026
Scotland’s non-domestic EPC method and certificate format are changing from 31 October 2026, including a move to a five year validity period and a one year transition for properties already on the market. Read our Scotland EPC changes update .
Our commercial EPC assessment process
Confirm scope. We confirm the address, approximate floor area, building use, tenancy arrangement and any constraints that affect access and evidence.
Survey and evidence capture. We complete a structured site survey covering fabric indicators, HVAC, controls and lighting and review available documentation.
Level 5 dynamic simulation modelling and calculation. We carry out Level 5 dynamic simulation modelling (DSM) assessments using IES VE, consistent with how we model and test building services design. This supports consistent, evidence led inputs for non domestic EPCs and reduces reliance on default data.
Lodgement. We complete internal quality checks, lodge the EPC on the relevant national register and issue the certificate pack.
What we capture on site
A non domestic EPC is only as reliable as its inputs. Our surveys focus on information that drives the rating and reduces avoidable default assumptions.
- O&M information and plant records, including plant type, efficiencies and evidence of controls strategy
- Plant rooms and roof spaces, including key equipment data and configuration relevant to the assessment
- Occupied and common areas, including lighting type, lighting controls, space layout and typical servicing approach
- Building fabric indicators, including glazing type and external element build ups where information is available
What you receive
- The lodged commercial EPC certificate and report reference number
- A short summary of key inputs, assumptions and evidence used
- Clear next steps if additional evidence could materially affect the result
- Practical improvement opportunities where appropriate
Why this matters: A clear EPC record reduces last minute queries during marketing, legal review and tenant decision making.
Cost and turnaround
The cost of a commercial EPC depends on building size, complexity, access arrangements and the availability of reliable records. Turnaround is most affected by access, multi let coordination and missing evidence that needs confirmation.
Information that helps us quote: address, approximate floor area, building use, tenancy arrangement and target date. If you have an existing EPC, include the report reference number.
EPC registers
If you are looking up an existing EPC, use the official register for the relevant jurisdiction. The GOV.UK lookup service also covers Northern Ireland. KJ Tait provides commercial EPC assessment and lodgement in England, Scotland and Wales only.
Exemptions
Some buildings may be exempt depending on building type and circumstances. Consider exemptions early so they do not affect programme.
Common exemption types (high level)
- Places of worship or buildings used for religious activities
- Temporary buildings intended for use for two years or less
- Low energy demand industrial sites, workshops or non residential agricultural buildings
- Detached buildings under 50 m² that are not dwellings
- Buildings due to be demolished where relevant consents and conditions apply
FAQs
What is a commercial EPC assessor
A commercial EPC assessor is accredited to assess a non domestic building, calculate the EPC rating using the approved methodology and lodge the certificate on the official register.
When is a non domestic EPC required
EPCs are commonly required when a building is sold, let to a new tenant or newly constructed. Requirements vary between jurisdictions and exemptions can apply.
How long is a commercial EPC valid
England and Wales: 10 years. Scotland: validity is expected to reduce to 5 years from 31 October 2026 as part of EPC reform. See our Scotland EPC changes update .
What affects a commercial EPC rating
Ratings are influenced by HVAC efficiency, controls strategy, lighting, fabric indicators and the quality of the input data. Missing evidence can increase reliance on default assumptions.
Do you use dynamic simulation modelling
Yes. We carry out Level 5 dynamic simulation modelling (DSM) assessments using IES VE. This is the same modelling approach we use for building services design and it supports consistent, evidence led inputs for non domestic EPCs, particularly on more complex buildings and refurbishments.
What do you need from us before you can provide a fee proposal
Address, approximate floor area, building use, tenancy arrangement, target date and any existing EPC report reference number. If available, include drawings and an O&M index.
Do you need access to tenant areas in a multi let building
Access requirements depend on what services and lighting are within landlord or tenant scope and what evidence is available. Where access is limited, we explain what inputs rely on defaults and what evidence would materially improve confidence.
What happens if O&M information or plant data is incomplete
We identify missing evidence, record the assumptions used and set out what additional information would materially affect the assessment. This helps avoid late changes during marketing or legal review.
Can you support EPC B planning and improvement works
Yes. Where you are planning upgrades to manage MEES risk or target EPC B, we can support an options review and phased plan through our EPC B Pathway service.
Key contact
Paul Miller
Chartered Engineer. CIBSE Level 5 Energy Assessor. Commercial EPC assessment and lodgement across England, Scotland and Wales.
If you send the building address, use type, approximate floor area and target date, we can confirm scope and provide a fee proposal.
Related guidance
MEES for non domestic property: EPC band E explained
A short guide for landlords on what EPC band E means under Minimum Energy Efficiency Standards (MEES) and what to plan next.
Read the MEES guideRelated guidance
EPC changes in Scotland: new method for commercial buildings
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Read the Scotland EPC changes updateRelated
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