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SAP Calculations - What are they? And why are they needed?

posted 25 Mar 2014, 03:38 by Unknown user   [ updated 23 Oct 2014, 08:48 ]
Why carry out a SAP (Standard Assessment Procedure) Calculation?

Under Approved Document Part L its states that all new dwellings and all buildings converted into dwellings require an SAP calculation to be carried out to demonstrate compliance with energy performance requirements. Some extensions and renovations could also need a SAP calculation to be carried out, particularly if there is a lot of glazing or the extension alters 25% of an element in the existing building.

SAP calculations are also required to demonstrate energy performance in the Sustainability benchmarks such as the Code for Sustainable Homes and in some planning conditions.

When should a SAP Calculation be carried out?

A SAP calculation should be carried out as early as possible in the Design Stage, getting them done in advance to work starting on site will allow for the energy efficiency of the dwelling to be considered whilst it is being designed ensuring a cost effective solution to compliance is achieved. If a SAP is not calculated at the Design Stage of a new dwelling, this could lead to the dwelling not complying with Part L1A at Post Construction Stage and expensive retrospective work may be
SAP Calculations

Do I need a SAP Calculation for every dwelling on site?

SAP calculations submitted for building control should demonstrate the performance of all the dwellings on the site. Due to the number of items that will cause the calculation to vary, a large proportion of the dwellings will require an SAP assessment and builders often have an SAP for every dwelling. This helps with Code for Sustainable Homes assessments.

Who carrys out SAP Calculations?

SES have Elmhurst Accredited SAP Assessors who can carry out professional SAP Calculations on new and existing buildings. We have extensive expertise in performing SAP Calculations meeting the Building Regulations of Approved Document ‘Conservation of Fuel and Power’ part L1A for new dwellings and L1B for existing dwellings.

What is the difference between a SAP Calculation and an EPC?

SAP is generally a term that describes the design stage DER/TER (Dwelling Emission Rate/Target Emission Rate) Calculation, an Energy Performance Certificate is calculated from an As-Built SAP and represents the dwelling as constructed included an air test result.

For FREE advice and to get a fast SAP calculation quote please call us on 01279 873354 or email us at