When an SBEM result misses Part L: a design-team response
A failed energy-model result is a prompt to test the actual design, not to change a number in isolation.
Confirm the model is describing the current building
Before redesigning a non-domestic project, check the SBEM input against the latest drawings. Are the floor areas, uses, glazing, fabric and building services still current? A result based on an old plan or placeholder plant specification can send the team toward the wrong fix. Record the drawing revision and the assumptions used for each calculation. Our SBEM input checklist helps identify what should have been supplied at the start.
Find the pressure point, then test options
An SBEM calculation can show where the proposed building differs from the required energy-performance targets under the applicable Part L route. Ask the energy modeller to explain which inputs and outputs drive the result. The project team might test alternatives for fabric, glazing, heating, cooling, ventilation, lighting or controls, but no single measure is a guaranteed solution. Check its effect on use, cost, comfort and coordination before specifying it. The official Approved Document L collection is the reference point for the edition applicable to the project.
Keep the calculation connected to the specification
If a design option improves the model, update the architectural and services documents together. A lower lighting-power input in SBEM is useful only when the selected fittings and controls will actually be installed. Name who owns each change, the revision it appears on and the evidence needed later. This prevents an apparently compliant design-stage calculation from drifting away from the building constructed.
Agree the next submission before work moves on
The building-control body and project team should confirm the required calculation stage, method and evidence for their scheme. A Part L compliance result, as-built SBEM output and commercial EPC serve related but different purposes. Send our SBEM calculations service the latest plans, specifications, prior model output and the decision date. We can then scope the next modelling iteration around a real design choice rather than a generic request to 'improve the rating'. Our design-to-as-built guide explains the later handover trail.