Stroma Built Environment delivers SAP calculations for new and existing residential properties to ensure your building stock is compliant with the Government’s Standard Assessment Procedure (SAP) and Part L of the Building Regulations.

With the update to Part L1a in June 2022, Stroma offers SAP 10 calculations to comply with the new regulations, as well as all past iterations of SAP from 2005.

With over 20 years’ experience in the industry, our expert team is ideally positioned to provide you with the best SAP design and compliance advice available to ensure your buildings meet all relevant regulations and standards.

  • Nationwide Delivery: Access a nationwide network of SAP Assessors and Air Tightness Engineers to arrange testing at short notice and around your build schedule.
  • Building Regulations Compliance: Fast and efficient reporting for full compliance and a smooth handover process.
  • Compliant SAP Software: Our expert assessors use MHCLG-approved software to complete SAP-compliant calculations, including FEE, SAP, and Environmental Impact Ratings.

What are SAP Calculations?

SAP is the methodology used by the UK Government to assess and compare the energy and environmental performance of dwellings. It is used to produce an Energy Performance Certificate (EPC) rating, which indicates a dwelling's energy efficiency.

Qualified assessors carry out the calculations to provide evidence that a property meets the requirements of Building Regulations Part L. This is often required for new builds, extensions, renovations, or changes in occupancy.

Accurately assessing the energy efficiency of a property helps support informed decision-making on how to improve it for better sustainability and cost savings in the future. As such, they are an indispensable part of any construction project.

They include several detailed assessments, including: 

  • An evaluation of all potential heat losses from glazing, walls, floors, and roofs.
  • An appraisal of how effective insulation measures such as cavity wall insulation could be.
  • A review of air leakage rates through windows, doors, and other openings.
  • Analysis of ventilation performance to ensure adequate fresh air supply.
  • A check of the efficiency of heating and hot water systems.

SAP Calculations for New and Existing Residential Developments

For all new builds, we recommend that you complete SAP calculations during the design stage to avoid costly and time-consuming redesigns later.

The calculations determine CO2 emission rates and annual energy costs (including space, water heating, and lighting) for domestic dwellings. If your specification is not on target to meet the required limits, or if design changes occur during construction, we can provide advice and additional calculations to ensure building regulations compliance.

We employ a certified team of SAP Assessors (On Construction Energy Assessors) who are highly experienced in completing calculations on challenging developments, including high-rise buildings and high-sustainability projects.

What Information is needed for SAP Calculations?

Our assessors will require various documents and information from the construction project. Having the relevant documents and details ready before beginning the calculations is essential to ensure an accurate assessment.

You will need to provide the following information:

  • Architectural plans
  • Structural drawings
  • Energy bills for the previous 12 months
  • Heating control details
  • Hot water systems
  • Ventilation details
  • Building fabric (incl. roof insulation, windows, and air tightness values)
  • Installed renewable technologies
  • Building regulations details

Types of SAP Calculations and EPC Certification

We provide a range of calculations and assessments to ensure your projects meet the necessary standards.

  • Design Stage SAP Calculations: Predict the energy performance of a building before it is built.
  • U-Value Calculations: Assess the thermal performance of elements within a building.
  • As-Built SAP Calculations: Measure the actual energy performance of a building once it has been constructed.
  • Predicted Energy Performance Certificate (EPC): Assigns each property with a SAP score which places it on a band from A to G.

Part O Overheating Assessments

Stroma also delivers BOTH Simplified and CIBSE TM59 assessments to demonstrate compliance with Approved Document O.

Click to find out more about Overheating Assessments