The architect has finished the building regs drawings and he tells me I need a SAP assessment, so he got a quote for the assessment and all it says is "carry out SAP assessment".

So what should I get for my money, is there a specification for a SAP assessment. Will I need to get another 'as built' assessment on completion.

SAP is the ‘Standard Assessment Procedure’ methodology used to demonstrate to a Building Control Body (BCB) that a building will be constructed in compliance with appropriate regulatory guidance and to compare performance of two or more dwellings.

All new dwellings must have an assessment of energy performance (SAP), environmental impact (EI) and building regulations compliance undertaken at the design stage of the build, prior to works commencement. Once the dwelling is built, that assessment is revisited, with an as-built version required on completion and used to produce the Energy Performance Certificate or EPC for short

SAP determines, in accordance with the European Performance of Buildings Directive (EPBD), the ‘energy performance of a building’, which includes within it the amount of energy actually consumed or estimated to meet the different needs associated with a standardised use of the building. This includes space heating, hot water heating, cooling, ventilation and lighting. It excludes non-regulated energy use, such as for cooking or appliances.

The cost and associated carbon equivalent emissions for different fuels for the calculated energy demand is determined by the software and this forms the basis of the energy efficiency rating (SAP rating) and of the Environmental Impact (CO2e rating). Which are the two ratings found on an Energy Performance Certificate for the completed dwelling.

The calculation considers the dwelling’s insulation, technical and installation characteristics, design and positioning in relation to climatic aspects, solar exposure and influence of neighbouring structures, own-energy generation and other factors, including indoor climate, all of which influences the energy demand.


Approved Document L1A (2013) for England and L1A (2014) for Wales and Scottish Building Standards Section 6 (2011) all give guidance as to how to reasonably demonstrate to Building Standards/Building Control that a building has been constructed in compliance with the appropriate energy efficiency requirements.

This is done through a Design stage energy assessment (SAP) submission before work starts and then an As Built (SAP) submission on completion, with both submissions showing that the dwelling will meet, or has met required targets (along with specifically how this is, or has been achieved).

The two submissions are used by Building Standards/Building Control to check compliance of the design and of what is actually built. A clear connection must be evident between product specifications and the data inputs into the compliance software used (following the SAP calculation procedure and conventions). The calculations for the As Built submission are used to produce the Energy Performance Certificate for the completed dwelling.

The two submissions are a mix of mandatory requirements, which must be achieved and statutory guidance, which if followed, demonstrates reasonable provision that the criterion from the regulations have been met.

Hope the above helps.

I got three things:
1. An Energy Performance Certificate
2. Confirmation that I would meet Building Regs
3. How many Code for Sustainable Homes points I would get for the relevant sections of the Code

It seemed to be quite an iterative process between the Architect and SAP Assessorr to make sure I got all of the Code points that I needed.

Will you be getting a Warranty for your self build? If you are, I found that some warranty companies would only deal with a single Building Control company (basically giving you no choice / making you look at the warranty & building control cost as a package). My Building Control company packaged in the SAP Calcs and offered no discount if I didn't want them to perform the Calcs. Basically I nearly got caught out paying for SAP Calcs twice. It might be worth sorting out a few elements before diving in.