Sap Calculations Wigan

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So, What Exactly Are Sap Calculations?

Have building control or your architect requested you to get sap calculations in Wigan. Why will you need them and what exactly are sap calculations anyhow? Then keep reading.

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



Wigan SAP Calcs For Dwelling Change Of Use

  • Reports for Part L1B Compliance
  • Free Advice

Wigan SAP Calcs For Overglazed Extensions

  • Carbon Emissions Reports
  • Heat Loss Calculations
  • Free Advice

Wigan SAP Calcs For New Builds

  • Reports for Part L1A compliance
  • Free Advice

What does SAP mean?

SAP stands for Standard Assessment Procedure and is the UK government’s means of determining the energy efficiency of properties. These calculations are required to show your building conforms with certain energy targets laid down within the building regulations.

That’s more or less it in a brief summary.


When Are SAP Calculations Needed?

The three main reasons Sap calculations are needed

1. For all new dwellings
2. For a dwelling change of use,for example altering a single family home to residential flats.
3. For overglazed extensions

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

A good set of building drawings must 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 additional guidance in the event the calculations show your dwelling isn’t compliant, as well as explain to you which will be the best improvements to make. It could be expensive if you find out at a late stage in the construction that the building is not compliant. So it is best to liaise with your Assessor as early on during the project as possible, ideally before any building commences.

If you need guidance on a project you could have in or around , or simply require a quote, give us a call or fill in our get a quotation form. We’re here to help.


Need to have an answer to a question you have about SAP calculations in Wigan? Here are the 10 most popular questions.

So, What Exactly Are Sap Calculations?

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

How Much Are Sap Calculations

This might differ considerably depending on the size and complication of the dwelling, but a typical cost range would be between £120 – £300. There will probably be a further fee of approximately £50 if an EPC is called for at the end of the build. Special discounts would typically be available for multiple dwellings especially when they are of the same style of building.

What Is The Difference Between Sap and EPC

Before we get to the differences, here is what you will need 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 put together to show the energy performance of a property. EPC means Energy Performance Certificate and it’s a summary statement from the SAP calculations in an straightforward document, which can also be used to sell or rent a property.

There are actually two types of EPCs. The first is a SAP EPC that is created from building plans where all of the elements of the construction are known. This would normally be required by building control to show that a dwelling complies with certain targets essential to the building regulations. Building control would must also see the SAP calculations which illustrates in greater detail whether all the components going into the property comply with the building regulations.

The second variety of EPC is the typical one that will be necessary for anybody who is selling, or renting a property. This particular EPC uses what’s called rdSAP, which means Reduced Data Standard Assessment Procedure, which is used where particular thermal values of, for example, the walls, roof, floors, etc, are not precisely known on an existing property. In this instance assumed thermal values are used depending on the age of the property. This kind of EPC would be no use to show compliance with any building regulations. Sometimes building control would simply ask you to get an EPC, but what they would really require are the Sap calculations (which is the data behind the EPC) and the SAP EPC (which is a summary report from the Sap calculations).

Still perplexed, then simply call us for further assistance.

What Are As Built SAP Calculations

These are the finished set of SAP calculations generated once the dwelling has been completed to confirm that it is compliant with Part L1A of the building regulations. Ahead of the construction starting, it should have had some “Design Sap” calculations to show that the proposed construction, in theory at least, would be compliant with Part L1A.



Can I Do The Sap Calculation Myself

Unfortunately this is not something you can do by yourself. The calculations have to be carried out by an On Construction Domestic Energy Assessor or OCDEA, by using approved Government computer software. The Assessor has to be certified under one of several certification schemes and is also regularly audited to keep up their certification.

What Info 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

All new dwelling need Sap calculations to show compliance with Part L1A (Conservation of fuel and power in new dwellings) of the building regulations.


Sap Calculations For Extensions

It’s now quite trendy to get large bi-folding doors, sky lights and large quantities of glazing on new extensions. However with the present building regulations the quantity of glazing must be no more than 25percent of the floor area of the new extension. So over compensations in the thermal elements in other places within the property will have to be made to demonstrate that the CO2 emissions coming from the current house and the proposed extension is no worse than the existing house and an extension where the glazing is within the permitted amount judged against Part L1B of the building regulations.

You will require SAP calculations to find solutions and show compliance.


Sap Calculations For Conversions

If you are modifying 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 to have 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. If you’re not certain whether you will need them, then phone us.


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 Wigan . We also cover the whole of the UK and can assist on any project nationwide.

Reliable & Fully Insured

You will be assigned a dedicated Assessor who is also covered by full professional indemnity insurance of up to £100,000 and that 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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