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SAP Calculations for New Build Developments.  

L1A – SAP calculations for new dwellings

In order to demonstrate compliance with Approved Document L1A you must provide your Building Control Officer with a SAP calculation for each new-dwelling.

A SAP calculation is the Government’s approved methodology for calculating the energy performance of dwellings. All new dwellings must achieve a dwelling CO2 emission rate (DER) no greater than a target CO2 emission rate (TER). The SAP calculation process is in three stages:

·         Design-stage

·         As-built stage

·         On Construction EPC

Our experienced SAP assessors can guide you smoothly through compliance, from concept to completion. Our service includes all the support required to ensure every dwelling can achieve a pass.

Design-stage SAP calculations

Design-stage SAP calculations, showing a pass, must be provided to Building Control before you start on site.

We will assess the dwellings based on the design-specification provided. If a pass is not achieved we will suggest cost effective options to achieve a pass. For example, improvements to the heating system, increase in insulation, a higher standard of glazing, or a more air-tight construction (see air leakage testing).

Once a satisfactory specification has been agreed we shall issue design-stage SAP reports for submission to Building Control.


As-built SAP calculation

As-built SAP calculations must be provided to Building Control as part of their final sign-off procedure.

Upon completion of the construction works we will update the design-stage SAP calculations to incorporate any changes to the design, manufacturer details for all heating systems and the as-recorded air permeability rate.

We will then issue as-built SAP report and produce the On Construction Energy Performance Certificate.  

To book an On Construction EPC Please call:

07792 972009


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