SBEM calculations for new non-domestic buildings
For a new building other than a dwelling, Approved Document L, Volume 2 describes whole-building energy assessment and associated compliance reporting. SBEM is one approved calculation route for suitable designs; approved simulation software may be appropriate where the building's features cannot be adequately represented in SBEM.
Approach our SBEM calculations service while the proposed use and services strategy can still be discussed. A warehouse with a staffed office and an attached workshop needs a clearer brief than simply commercial unit. Identify the activities and heating arrangements in each space so that the assessor can understand what is being built.
Commissioning the assessment early gives the design team an opportunity to compare workable specifications. If the first model is produced after equipment has been purchased, the available responses become narrower. Ask the quote to identify design review, reporting and later updates rather than treating the calculation as a single file delivered without further involvement.
When extensions need an SBEM calculation route
An extension is not automatically assessed in the same way as an entirely new building. Approved Document L, Volume 2 distinguishes extension cases and provides routes involving fabric and services standards, with some extensions treated using new-building guidance. Confirm the applicable route against the actual proposal rather than applying a rule remembered from another project.
Send drawings that distinguish the existing building, the new area and the openings connecting them. Explain whether the new space has its own systems or shares plant with the original premises. The relationship matters when deciding what the assessment should cover and what information is needed from the existing building.
For a proposed office addition, for example, identify which existing rooms will also be changed. A project described as an extension may include replacement lighting, altered ventilation and a new heating arrangement elsewhere. Keep those activities visible in the scope so that an extension-only appointment does not leave the rest of the works unexplained.
SBEM questions for conversions and changes of use
The words change of use can refer to different processes. The Building Regulations provisions for material change of use and energy work are addressed in Approved Document L. A planning description should therefore be accompanied by a practical account of the existing and proposed accommodation, rather than being treated as a complete energy-assessment brief.
If a building will contain both flats and business space, mark the boundary between them and identify shared services. Our SAP vs SBEM guide explains the domestic and non-domestic distinction. A mixed proposal may need coordinated assessments rather than a single method selected for the whole address.
Where planning energy evidence is requested, check the actual condition or local application requirements. Planning requirements differ by council, and the official planning application guidance explains the role of local information requirements. Send the wording to the assessor so that a Building Regulations calculation is not assumed to discharge a separate planning request.
SBEM calculations during fit-out and refurbishment
Refurbishment does not always create a requirement for a complete new-building calculation. Approved Document L, Volume 2 includes provisions for work to existing buildings, including controlled services and fabric. Establish which parts of that guidance apply before ordering a full model or assuming that no evidence is needed.
For a tenant fit-out, collect the landlord's existing energy documents and any stated design assumptions. The previous model may have used an indicative services arrangement. Compare it with the tenant's actual proposals and ask who is responsible for resolving any difference. Use our BRUKL report guide to check the report stage and scope.
- Describe the previous use, proposed activities and which parts of the premises remain unchanged.
- Identify retained equipment separately from new heating, cooling, lighting and ventilation installations.
- Provide shell-stage documents and explain any landlord or tenant boundaries that affect the available evidence.
Information that settles whether SBEM calculations are needed
A sale or letting may require an EPC under the GOV.UK commercial EPC guidance, even when no construction project is under way. Tell us whether the request comes from an agent, Building Control, a designer or a planning officer. The recipient and purpose help distinguish certification from demonstrating compliance for building work.
Use our support for developers where several units or phases need coordinated appointments. For a specific enquiry, send our SBEM calculations service a description of the works, existing and proposed drawings, intended uses, services information and the exact wording of any outstanding request. Ask for the proposed assessment boundary and reporting scope to be confirmed before authorising the work.