SBEM & DSM Calculations — Building Regs Part L

When in the project should I instruct you?

As early as RIBA Stage 2/3. Early modelling is the cheapest way to reach Part L compliance and avoid expensive late design changes.

Do you provide the on-construction EPC?

Yes — we lodge the on-construction EPC at practical completion as part of the as-built submission.

Can you cover overheating (Part O / TM59)?

Yes — TM52 and TM59 overheating analysis is delivered alongside SBEM/DSM where Part O or planning requires it.

What's the difference between SBEM and DSM?

SBEM is the simplified compliance tool for typical buildings. DSM uses dynamic modelling for complex geometry, mixed-mode ventilation, atria or large glazed buildings where SBEM would over- or under-estimate performance.

Do you work to Part L 2021 and the Future Buildings Standard?

Yes — all modelling is delivered against current Part L 2021 uplifts, with optional FBS-readiness analysis to futureproof the design.

Can you advise on fabric and services trade-offs?

Yes — early-stage advisory compares U-values, glazing ratios, ventilation strategies, heat pump options and renewables to find the lowest-capex compliant solution.

Will you liaise with Building Control?

Yes — BRUKL documents and supporting evidence are issued directly to your Approved Inspector or Local Authority Building Control as required.

Is on-site PV factored into the model?

Yes — Solar PV, heat pumps, MVHR and other low/zero-carbon technologies are modelled within the SBEM/DSM submission to demonstrate Part L compliance.

How long does modelling take?

Initial design-stage SBEM is typically 1–2 weeks from receipt of drawings. As-built models are usually issued within a week of practical completion data.

Can you cover refurbishments and Material Change of Use?

Yes — we model refurbishments, extensions, fit-outs and Material Change of Use projects to demonstrate compliance with Part L Approved Document L2B.