SAP Calculations

epc4less is an award SAP Assessment Agency established in 2007. We specialise in providing SAP Calculations within the new build environment.

Whether your project is a domestic or a commercial construction we can assist with the following:

• SAP assessments for new builds


• SAP assessments for extensions, or large glazed extensions


• SAP assessments for conversions

Why Are SAP Assessments so important?

SAP assessments are an important element in the design process because they set the metrics for the energy efficiency of a proposed dwelling as well as the reflected CO2 emissions. The methodology is called SAP which stands for Standard Assessment Procedure.

Part of the SAP assessment is the Energy Performance Certificate (EPC) which shows the projected energy rating of the dwelling on a scale from 0 to 100, where zero is very poor and 100 is very high.

What areas do we cover?

We work nationwide. All SAP assessments can be done remotely using architects drawings. We are experienced in the building regulations of all regions in the UK. So whether your project is in England, Wales, Scotland or Northern Ireland, we can create SAP calculations and compliance documents for your regional building regulations.

What information is required to produce SAP reports?

We start our work using the following drawings:

• Elevations


• Floorplans


• Sections


• Site plans

We also need to know building fabric details so we can produce the u values of walls, roofs and floors.

How long does it take to produce a full SAP assessment?

As long as we have all the required documentation, it will take approximate a week to complete the SAP assessment of an average size new build.

What are the key metrics of a successful SAP Assessment?

Low u values. The u value is a metric that determines the thermal resistance of a material. The lower the u value the better. The u values determine the dwelling’s fabric energy efficiency (DFEE) which must be less than the Target Fabric Energy Efficiency (TFEE)

Meeting the TER value. TER, which stands for Target Energy Rating, is based on the choice of heating system and heating controls. A SAP assessment will produce the Dwelling Energy Rating (DER) which must be less that the TER.

Our team of SAP Assessors have a wealth of experience in calculating the above metrics. We have a huge record of u values for hundreds of wall, roof and floor structures. We are available to advice homeowners, architects and developers on the use of building fabric, renewable energy or overheating issues, and of course prepare SAP Calculations and compliance documents for Building Control.