SAP Calculations For Extensions

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SAP Calculations For Extensions

Why Your Extension Needs SAP Calculations

L1B SAP calculations are required for certain extensions to make sure your extension complies with Part L (England & Wales) of The Building Regulations. SAP calculations for extensions are concerned with energy efficiency. This is part of the government’s plan to reduce carbon emissions and tackle fuel poverty. 

SAP Calculations With UKBC

We recommend you commission your calculations at design stage. Therefore, should your building be failing to meet requirements, our team can advise you on how to improve. This is far easier and cheaper at design stage, when the scope of possible changes is more flexible.

UKBC L1B SAP calculations for extensions come in two stages: a ‘notional report’ and a ‘proposed report’. We compare these reports in order to demonstrate that the whole property as constructed, will meet Part L1B Standards.
Our process includes:

  • Assessing the existing and proposed area of the external building fabric and openings. 
  • Evaluating the building's current construction materials and the extension's proposed materials. 
  • Measuring the energy consumption of the current and updated heating systems, lighting, ventilation systems and renewable technologies.
  • Next, we create 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 plus the extension.
  • Finally, we’ll analyse and compare the reports in SAP calculations software to make sure the data in the proposed report is lower than benchmarked standards.

What We Require

  • Floor plans for both the existing and proposed property 
  • Elevation drawings for both the existing and proposed property
  • A section drawing displaying the height of each floor
  • Specification of the proposed elements e.g. wall, floor, roof & glazing
  • Heating system details