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Sap Calculations London

A group of very skilled Assessors delivering sap calculations close to you. E mail us to get a quotation on your venture.

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Sap Calculations, What Exactly Are They?

For anyone who is reading this, you’ve more than likely been recently asked by another person, normally your building control officer, to supply sap calculations for your building project.

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

SAP is short for Standard Assessment Procedure and is the United Kingdom government’s procedure for calculating the energy performance of buildings. These calculations are necessary to demonstrate your building conforms with specified energy targets laid down in the building regulations.

As a short summary, that’s pretty much it. 

Sap Assesments are usually required for three main reasons

  • For all newly built properties.
  • For a dwelling change of use, such as changing a commercial building to residential flats.
  • For overglazed extensions|{Sap calculations are usually required for three main reasons.

The sap calculations are required to establish that the dwelling emission rate (DER) and the dwelling fabric energy efficiency (DFEE) conform to specific targets.

The calculations will be carried out by a certified and approved On Construction Domestic Energy Assessor. There is no need to visit the property as all of the calculations are carried out from the building plans ,so a good set of plans are very important. 

An EPC or Energy Performance Certificate can be produced once the calculations are finished.

Your Assessor can provide additional guidance in the event the calculation show your dwelling isn’t compliant, as well as let you know which will be the most effective changes to make.

It can be costly if you realise at a late phase in the construction that your 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 London, or require a quotation, give us a call or fill in our get a quotation form. We’re here to help.

Sap Assessor

SAP Calculations in London The 10 Most Frequent Queries Asked.

What Are As Built SAP Calculations

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



Sap Calculations, What Exactly Are They?

This really is by far the most frequent question asked. Take a look at Andrea’s video explanation above, or read the full explanation here on the right.

How Much Do Sap Calculations Cost
We will be pleased to offer discounts, especially for multiple dwellings which are of the same or similar construction. For individual properties you would then be looking in the region of £120 – £300 depending on the intricacy of the building and the size. By providing the plans, it will be possible to get yourself a fixed price quotation.
How To Do Sap Calculations

Unfortunately this is not something you can do by yourself. The calculations must be carried out by an On Construction Domestic Energy Assessor or OCDEA, working with approved Government program. The Assessor must be certified under one of several accreditation schemes and is regularly audited to keep their certification.

What Info is Needed For A Sap Assessment

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 Assessment 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 regulations.

Sap Calculations For Extensions
It’s now popular to get large bi-folding doors, sky lights and large amounts of glazing on new extensions. However under the latest building regulations the quantity of glazing must be a maximum of 25percent of the floor area of the new extension. Therefore over compensations in the thermal elements in other areas within the property will need to be made to show the CO2 emissions coming from the current house along with the proposed extension is not any worse when compared to the existing house and an extension whose glazing is within the allowed amount judged against Part L1B of the building regulations.

You need SAP calculations to find solutions and demonstrate compliance.


Sap Calculations For Conversions
If you are changing the use of a building, you will require Sap calculations. {The new dwelling will have to comply with Part L1B of the building regulations.}


Will I Need Sap Calculations
p>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 unsure whether you need them, then simply phone us.


Our Services


SAP For Dwelling Change Of Use

  • Reports for Part L1B Compliance
  • Free Advice

SAP For Overglazed Extensions

  • Carbon Emissions Reports
  • Heat Loss Calculations
  • Free Advice

SAP For New Builds

  • Reports for Part L1A compliance
  • Free Advice

What You Can Expect From Us

Trusted & Experienced

Our Assessors are fully qualified and accredited with years experience carrying Sap calculation in London . 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 so 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 aim to provide 100% customer satisfaction and look forward to working with you.


Get A Quote, Or Call Us For Advice