Sap calculations for extensions

UKBC are registered SAP Assessors with Stroma.

L1B SAP calculations are required for certain extensions to make sure your extension complies with Part L (England & Wales), Section 6 (Scotland) or Part F1 (Northern Ireland) of the most recent version of The Building Regulations.

SAP calculations are concerned with energy efficiency and are necessary to produce an updated Energy Performance Certificate (EPC) for the property. An EPC is required by law to rent or sell a home. This is part of the government’s strategy to reduce carbon emissions and tackle fuel poverty.

UKBC recommends that you have SAP calculations carried out as early on in the project as possible, in order to put right any factors that may cause your extension to fail the SAP at the design stage.

UKBC L1B SAP calculations for extensions come in two stages: a ‘notional report’ and a ‘proposed report’. These reports are then compared in order to produce an up-to-date EPC for the entire property. This process includes:

  • Assessing the existing and proposed area of the external building fabric and openings
  • Assessing the building’s current construction materials and the extension’s proposed materials
  • Assessing the energy consumption of the current and updated heating systems, lighting, ventilation systems and renewable technologies
  • Creating a notional report with benchmarked data for the existing and proposed elements of the building, and a report with the proposed data for the existing building and the extension
  • Assessing the building’s current construction materials and the extension’s proposed materialsnputting data from the proposed report into SAP calculations software in order to determine the entire property’s Dwelling Emission Rate (DER) and Dwelling Fabric Energy Efficiency (DFEE) rating
  • The DER and DFEE of the proposed report is then compared against benchmarked standards; for extensions to pass the SAP, the figures from the proposed report must be lower than the benchmarksAssessing the energy consumption of the current and updated heating systems, lighting, ventilation systems and renewable technologies

UKBC will guide you through the entire process of getting L1B SAP calculations for extensions, including consultation on how to make sure your extension passes. For more information or to arrange testing, contact us today on 01455 634855 or request a QUICK QUOTE.