SAP Extension Calculations / SAP Extension Assessment are a Government defined process in accordance with Part L1B Building Control Regulation Compliance of Domestic Property. SAP Calculations are the Government's Standard Assessment Procedure for Energy Rating of Dwellings.

Since 6th April 2006, Part L1B has required SAP Extension Calculations to be carried out on every new conversion.

You will automatically achieve Compliance with Part L1B if the extension envelope is sufficiently insulated, the area of all openings is within the 25% allowance and building service are sufficient.

All SAP Extension Calculations are calculated in accordance with Part L1B of the building regulations.

The Calculation is produced by creating a notional and proposed version of the entire dwelling. The notional dwelling is the current building with the extension, this has the known current U-Values of the building and the proposed extension defaulted to the L1B 'Upgraded Thermal Elements' standards. This ‘Notional’ SAP Calculation provides a calculated level of annual carbon dioxide emissions which in-turn provides a target threshold for the proposed works. The proposed building will be the same but with the actual proposed U-Values that are going to be used for the new thermal elements and openings. The associated annual carbon dioxide emissions are then compared to the previously calculated target rate.

Conversely, if the proposed extension carbon dioxide emissions are greater than the calculated target threshold, then trade-off improvements will be required to either the extension specification or the existing house as a means offsetting the additional heat loss associated with the extra levels of glazing within the proposed extension above the standard threshold detailed within the Building Regulations.

Whether you're an architect, self builder, developer or homeowner, we can help. We deal with singular plots right up to large residential sites.

At E2 Consultants we pride ourselves on being able to provide all of the Part L services. As well as SAP Calculations we provide On Construction EPCs, SBEM calculations, Air Tightness / Pressure Testing, Sound / Acoustic Testing, Code for Sustainable Homes (C4SH) Assessments / BREEAM assessments with consultancy. As part of our service we advise our clients as to how they can best achieve compliance in the most cost-effective manner, for this reason all of our SAP Conversion calculations are site-specific. Alterations are free of charge and our SAP Assessors will also liaise with Building Control Officers on your behalf.

We can also provide you with an On Construction Energy Performance Certificate (EPC), they are produced using the SAP Methodology and are undertaken by one of our On Construction Domestic Energy Assessors (OCDEAs). The certificates are needed if a property is to be sold or let, they can also be requested by Building Control. Your initial SAP Assessor may not be qualified to produce On Construction EPCs but E2 Consultants are able to produce your On Construction Energy Performance Certificate (EPC) even if we didn't complete your initial SAP Calculation.

E2 Consultants will try to beat any other price that you might receive. Call one of our regional offices and speak to one of our sap Extension calculation experts on 0800 043 8100 for a formal quotation.

SAP Extension Calculations can also be known as:
SAP Extension Assessment,