SAP Calculations for new builds

What are SAP Calculations?

SAP stands for Standard Assessment Procedure and is adopted by Government as the UK methodology for estimating the energy performance of a new dwelling, conversion or extension.

Using state of the art computer modelling software, the SAP Calculation determines a number of indicators of energy performance including, an energy cost rating (the SAP rating), an environmental Impact rating based on CO2 emissions (the EI Rating) and a Dwelling CO2 Emission Rate (DER)

Building Regulations require that a SAP Calculation and a Predicted EPC is submitted for new dwellings prior to the commencement of work on site.  

Essentially, the SAP calculation is the means of showing your approved Building Control Body that your new build complies with energy and carbon requirements set out in the latest 2021 Part L1 Building Regulations.

When do I need SAP Calculations?

For all new builds, including conversions and extensions`, we recommend that you complete SAP Calculations during the design stage to help avoid costly and time-consuming redesigns later.  This is an ideal time as many local authorities require an Energy Strategy to be completed at planning stage to accompany a planning application, to learn more about how we can assist with Energy Strategy planning requirements please click here.

The SAP Calculation will need to be submitted to Building Control with your Building Regulations application.

Once the development is completed an As Built SAP Calculation and EPC must be submitted to Building Control for final approval.

Are SAP Calculations just for New builds?

Not at all, Many extensions, conversions and change of use schemes will require SAP Calculations;

  • Extensions with more than 25% glazing-to-floor area (SAP Calculations for Extensions)
  • Barn Conversions
  • Commercial to domestic conversions (Change of Use)
  • Conversion of single dwelling into flats or apartments/ HMOs

What information do we need to provide for you to complete a SAP Calculation?

Typical time line of a SAP with Melin Consultants;

Initial Enquiry

(please contact via 01554 571010 or click here )

One of our dedicated team members will explain what we need to send across a fee proposal,

a set of drawings or a brief description of the project will suffice at this stage

We send you a comprehensive competitive fee proposal (with no hidden costs) and a full break

down of how we will assist with your project along with what information we will require if instructed.

Once instructed, and on receipt of all information, we can make a start, our standard leadtimes are 5-7 working days, with fast track options available if time is tight.                               

Your project is then assigned to one of our leading in house technicians who will contact you to introduce themselves and have a run through of the project

SAP Calculations are completed,  you are contacted again where the specialist will discuss the specification used to achieve compliance, if further options/iterations are sought at this stage, we will produce these at no extra cost.

The draft report is then checked and verified by at least one other in house Part L specialist.                                                                                                                                                

Final BREL or BRWL (Building Regulations England / Wales Part L) report, overview & Guidance document is issued, the overview and Guidance document are very important as it breaks down the full specification that we have proposed to achieve compliance, see an example of an overview here, whilst the guidance document explains what photographic evidence you will need to include ready for As built stage.                                          

Follow up contact a few days after to check that you are happy with the report and to answer any queries you may have.

We will then be on hand to answer any queries that may crop up during the course of the build, it is vitally important to notify us of any design changes as these could affect compliance at as built stage and the final as built SAP calculation & EPC.

Please note, in addition to SAP calculations, Building Control also require Part O Overheating Assessment and Part G Water Efficiency Calculations at design stage.  Please contact for further information on these services.

For more information or to request a SAP please get in touch.

Get in touch

Melin Energy Consultants

01554 571010

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