Guidance · 6 min
What information is needed for a SAP calculation?
A practical drawing and specification checklist for design-stage and as-built assessments.
Start with the drawing package
For a design-stage assessment, send dimensioned plans, elevations and sections for every dwelling type. The information should establish orientation, exposed elements, floor areas, storey heights, openings and the relationship with adjoining buildings.
Add the energy specification
Include proposed wall, roof and floor build-ups; window and door performance; heating and hot-water systems; ventilation strategy; airtightness target; renewables; and the intended approach to thermal bridging. Product selections can remain provisional if the performance assumptions are clear.
As-built information
At completion, the assessment must reflect what was actually built. Record substitutions, final product data, test results and evidence requested for the applicable assessment route. Flag changes early: apparently small substitutions can affect several inputs.
If the information is incomplete
A quotation can still be prepared from an early drawing set. We will identify the missing inputs and distinguish between assumptions suitable for an initial model and evidence needed before final issue.
Building Regulations guidance and assessment methods can change, and transitional provisions may apply. Confirm the correct route for the particular project rather than relying on a general article.