Sap Calculation Company Chester

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Sap Calculations, Exactly What Are They

Have building control or maybe your architect asked you to get sap calculations in Chester. Why will you need them and what exactly are sap calculations anyhow? Then continue reading.

You can click on the video on this page, where Andreas will shed some light on this, or read on.



Chester SAP Calcs For Dwelling Change Of Use

  • Reports for Part L1B Compliance
  • Free Advice

Chester SAP Calcs For Overglazed Extensions

  • Carbon Emissions Reports
  • Heat Loss Calculations
  • Free Advice

Chester SAP Calcs For New Builds

  • Reports for Part L1A compliance
  • Free Advice

What does SAP mean?

SAP is short for Standard Assessment Procedure and its the UK government’s way of calculating the energy performance of buildings. The calculations are required to illustrate that your building complies with certain energy targets laid down in the building regs.

In a quick overview, that’s essentially it.


When Are SAP Calculations Needed?

Sap calculations usually are required for three main reasons

1. For all new dwellings
2. For a dwelling change of use, such as converting a commercial building to domestic flats.
3. For a planned extension having in excess of 25 % glazing

The 2 main areas which the sap calculations will be looking at is that the carbon emissions from the dwelling are within set tolerances and that particular components of the property, for example the walls, roof, floors, and windows comply with specified thermal targets.

A good set of building drawings will need to be given to the Assessor, because all the calculations are done from the building drawings . Your Assessor will advise you of precisely what is needed. After the calculations are finished, an Energy Performance Certificate or EPC can also be created.

Your Assessor can provide further guidance if the calculation show your building isn’t compliant, as well as let you know which would be the best improvements to make. It might be expensive if you realise at a late stage in the construction that your building isn’t compliant. So it’s best to liaise with your Assessor as early on in the project as possible, ideally before any building commences.

Should you need guidance on a project you may have in , or require a quote, call us or fill in our get a quote form.


Rather than trawl through a entire website to find the answers you’re seeking, we have given answers to the ten most usual questions asked about SAP in Chester.

Sap Calculations, Exactly What Are They

This is probably the most frequent query asked. Check out Andrea’s video explanation above, or read the full explanation here on the right.

Sap Calculations, How Do They Cost

This can can vary considerably depending upon the measurements and complexity of the dwelling, however an average price range will be between £120 – £300. There may be an extra fee of approximately £50 if an Energy Performance Certificate is required at the end of the build. Reductions would typically be available for a number of dwellings especially when they are of the identical form of construction.

What’s The Difference Between Sap and EPC

Before we explain the difference, here is what you will require depending on your project.

For a new build property you’ll need – SAP calculations and an EPC.

For dwelling change of use or conversion you’ll need – Sap Calculations and an EPC.

For overglazing on an existing dwelling you’ll – Sap calculations only.

SAP or Standard Assessment Procedure are the calculations of pre defined data set of a buildings design that’s created to show the energy performance of a dwelling. EPC stands for Energy Performance Certificate and it’s a summary statement of the SAP calculations in an easy to understand document, that could also be used to sell or rent out a property.

There are really two types of EPCs. First is a SAP EPC which is created from building plans where all of the components of the building are known. This would normally be needed by building control to demonstrate that a property satisfies certain targets essential to the building regulations. Building control would also need to see the SAP calculations which shows in greater detail whether the many elements going into the property comply with the building regulations.

The 2nd type of EPC is the common one that will be necessary if you are selling, or renting out a property. This kind of EPC uses what’s called rdSAP, which stands for Reduced Data Standard Assessment Procedure, and is used where specific thermal values of, for instance, the walls, roof, floors, etc, usually are not precisely known on an established property. In this instance assumed thermal values are used according to the age of the property. This kind of EPC will be no use to demonstrate compliance with any building regulations. Sometimes building control would simply ask you to get an EPC, however what they would really require are the Sap calculations (which is the information behind the EPC) and the SAP EPC (which is a summary report of the Sap calculations).

Still perplexed, after that give us a call to get more assistance.

What Are As Built SAP Calculations

These will be the finished set of SAP calculations produced when the dwelling has actually been completed to hopefully demonstrate that it is compliant with Part L1A of the building regulations. Prior to the construction starting, it should have had some “Design Sap” calculations to demonstrate that the proposed construction, in theory at least, will be compliant with Part L1A.



Can I Do The Sap Calculation Myself

No, this is not some thing that you can do yourself. The calculations have to be carried out by an On Construction Domestic Energy Assessor or OCDEA, by using approved Government software. The Assessor has to be approved under one of several certification schemes and is regularly audited to keep their certification.

What Information is Needed For Sap Calculations

Your Assessor would advise you of exactly what is needed. Typically you would need the following:

  • Floor Plans to include sections and elevations
  • Orientation of the property
  • Construction specification of walls, roof and floors
  • Specification for all doors and windows
  • Primary and secondary heating
  • Provision for providing  hot water
  • Any renewable technology (if any)


Sap Calculations For New Build

Every new property need to have Sap calculations to prove compliance with Part L1A (Conservation of fuel and power in new dwellings) of the building regs.


Sap Calculations For Extensions

It’s now modern to have large bi-folding doors, sky lights and large quantities of glazing on new extensions. However with the existing building regulations the amount of glazing can be a maximum of 25% of the floor area of the new extension. Therefore over compensations in the thermal elements in other areas of the property will need to be made to show that the CO2 emissions coming from the existing house along with the proposed extension is not any worse when compared to the existing house and an extension where the glazing is within the allowed amount judged against Part L1B of the building regulations.

You need SAP calculations to find solutions and show compliance.


Sap Calculations For Conversions

For anyone who is changing the use of a dwelling, you will need Sap calculations. {The new dwelling will have to comply with Part L1B of the building regulations.}


Do I Need Sap Calculations

You will need Sap calculations for any of the following: 

  • Building a new property
  • Changing the use of an existing property (e.g, a barn conversion, commercial building to residential)
  • Extensions with more than 25% glazing
  • Opening up the main house to an existing conservatory
  • Extension where the extension is more than 50% of the original property wall area
  • Garage conversions
  • If requested by building control

This checklist is not exhaustive. Contact us, if you are uncertain if you require them.


Our Services

What You Can Expect From Us

Trusted & Experienced

Our Assessors are fully certified and accredited with many years experience carrying Sap calculation in Chester . We also cover the whole of the UK and can assist on any project nationally.

Reliable & Fully Insured

You will be allocated a dedicated Assessor who is also covered by full professional indemnity insurance of up to £100,000 which means you know you’re in save hands.

Prompt Service

We’ll respond to your enquiry within 24 hours. We’ll also help you to deliver your project within your timescale.

Satisfaction Guaranteed

We seek to provide 100% satisfaction and look forward to working with you.


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