Price on request
SAP calculations assess dwelling energy performance using information about its design and building systems. Project stage and available specifications determine the information needed.
SAP is the Standard Assessment Procedure used to calculate the energy performance of dwellings. A SAP assessment uses detailed information about a proposed or completed home, including its construction and building services. It supports the applicable energy compliance process and production of an appropriate new-dwelling EPC, with requirements determined by the project and relevant regulations.
The model brings together geometry, insulation performance, openings, thermal bridging, heating, hot water, ventilation and relevant renewable systems. Design-stage calculations use the proposed specification; as-built work must reflect what was actually installed. The assessment is one part of a wider compliance process and does not replace structural design, ventilation design or building-control approval.
Developers, self-builders, architects and owners creating new dwellings or undertaking certain conversion projects may need SAP calculations. Involving the assessor while specifications can still change helps identify potential issues before construction is complete. Explain whether the instruction is for design-stage advice, an as-built assessment or both, and identify the building-control route.
Provide dimensioned plans, elevations and sections, construction build-ups and product specifications. Include information about heating, ventilation, glazing and any proposed renewable systems. For completed work, gather installation evidence and applicable test results. Tell us when plans or products change so assumptions can be reviewed rather than carried forward incorrectly.
The agreed deliverables may include calculations, compliance outputs and an EPC at the appropriate stage. The quotation will identify which stages are included and whether revisions are covered. Retain the supporting evidence with the project records. Early assessment can help compare options, but a design-stage result is not a guarantee of the finished building’s outcome.
Tell us the details relevant to your property.
No. SAP generally uses detailed design and construction information. Existing-home EPCs usually follow a reduced-data assessment route.
Ideally while the design is being developed, before insulation and building-services specifications are fixed or installed.
Design-stage assessment relies heavily on drawings and specifications. Final outputs require suitable as-built information and evidence for the project.
Provide the number of dwellings, project type, plans, stage of work and whether design-stage, as-built or both services are required.
Further reading: GOV.UK: Standard Assessment Procedure.