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Sap Calculations Westminster

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So, Exactly What Are Sap Calculations

Have building control or perhaps your architect asked you to get sap calculations in Westminster. Why will you need them and precisely what are sap calculations anyhow? Then read on.

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



Westminster SAP Calcs For Dwelling Change Of Use

  • Reports for Part L1B Compliance
  • Free Advice

Westminster SAP Calcs For Overglazed Extensions

  • Carbon Emissions Reports
  • Heat Loss Calculations
  • Free Advice

Westminster SAP Calcs For New Builds

  • Reports for Part L1A compliance
  • Free Advice

What does SAP mean?

SAP is short for Standard Assessment Procedure and it is the UK government’s procedure for determining the energy performance of dwellings. Sap calculations are needed to prove that your building complies with certain energy targets laid down in the building regs.

That’s more or less it in a simple overview.


When Are SAP Calculations Needed?

Sap calculations usually are required for three main reasons

1. For all new homes
2. For a dwelling that’s changed its use, for example altering a commercial building to residential flats.
3. For extensions that have more than the permitted amount of glazing

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

A good set of building drawings must be given to the Assessor, as all the calculations are done from the building drawings ,so there is no need to visit the property. Your Assessor will advise you of precisely what is needed. After the calculations are completed, an Energy Performance Certificate or EPC can also be created.

If your sap calculations reveal that your property isn’t compliant, then your Assessor will give you information on upgrades that may be made to make it so. It’s crucial that you liaise with the Assessor as early on in your project as possible because once the building is finished any non-compliances could possibly be quite costly to rectify.

If you require advice on a project you may have in , or simply require a quote, contact us or fill in our get a quote form. We’re here to help.


Questions About Westminster Sap Calculations, see whether we have an answer here.

So, Exactly What Are Sap Calculations

This is by far the most common query asked. Have a look at Andrea’s video explanation above, or read the full explanation here on the right.

Sap Calculations, How Much Are They

If there are a number of properties with similar forms of constructions, then special discounts may apply. For individual properties you would be looking in the range of £120 – £300 dependant upon the intricacy of the construction and also the dimensions. By providing the plans, it will be possible to get a fixed quote.

What Is The Difference Between Sap and EPC

Before we get to the differences, here is what you will need depending on your job.

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 display the energy performance of a property. An EPC or Energy Performance Certificate is a overview report created from the Sap calculations which produces a SAP rating from 0 to 100. This rating is expressed on the Energy Performance Certificate as A the highest to G the lowest. It will also list suggestions that would enhance the rating of the property.

There are actually two types of EPCs. First is a SAP EPC that is produced from building plans where all the components of the construction are known. This would normally be required by building control to demonstrate that a property satisfies certain targets required by the building regulations. Building control would must also see the SAP calculations which shows in detail whether all of the components going into the property comply with the building regulations.

The second form of EPC is the common one that will be needed for anybody who is selling, or renting a property. This type of EPC uses what’s called rdSAP, which is short for Reduced Data Standard Assessment Procedure, and is used where particular thermal values of, for example, the walls, roof, floors, etc, are not precisely known on an existing property. In this situation assumed thermal values are used according to the age of the property. This type of EPC would be no use to demonstrate compliance with any building regulations. Sometimes building control would simply ask you for an EPC, however what they would really need to have 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 give us a call 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. Prior to the construction starting, it ought to have had a set of “Design Sap” calculations to demonstrate that the proposed dwelling, on paper at least, would be compliant with Part L1A.



How To Do Sap Calculations

No, this is not some thing you could do yourself. The calculations must be done by an On Construction Domestic Energy Assessor or OCDEA, using approved Government program. The Assessor has to be certified under one of the accreditation schemes and is also regularly audited to maintain 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

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


Sap Calculations For Extensions

It’s now popular to have large bi-folding doors, sky lights and large quantities of glazing on new extensions. But under the present building regulations the quantity of glazing can be a maximum of 25percent of the floor area of the new extension. So 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 current house and the proposed extension is no worse when compared to the existing house and an extension whose glazing is within the permitted amount judged against Part L1B of the building regulations.

You need SAP calculations to find solutions and demonstrate compliance.


Sap Calculations For Conversions

When 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.}


Will 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 is not an exhaustive checklist. If you’re not certain whether you will need them, then contact us.


Our Services

What You Can Expect From Us

Trusted & Experienced

Our Assessors are fully qualified and accredited with years practical experience carrying Sap calculation in Westminster . We also cover the whole of the UK and can help on any job nationwide.

Reliable & Fully Insured

You will be allocated a dedicated Assessor who is also covered by full professional indemnity insurance 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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