Sap Calculations Birkenhead

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Exactly What Are Sap Calculations

For anyone who is reading this article, you’ve probably been requested by someone, usually your building control representative, to provide sap calculations for your building project. But you probably haven’t been told what sap calculation actually are and why you need them.

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



Birkenhead SAP Calcs For Dwelling Change Of Use

  • Reports for Part L1B Compliance
  • Free Advice

Birkenhead SAP Calcs For Overglazed Extensions

  • Carbon Emissions Reports
  • Heat Loss Calculations
  • Free Advice

Birkenhead 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 way of determining the energy performance of buildings. The calculations are required to prove that a building complies with certain energy targets set down within the building regs.

That’s pretty much it in a simple summary.


When Are SAP Calculations Needed?

Here are most of the reasons you may well be asked for sap calculations

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

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

A good set of building plans must be given to the Assessor, as all the calculations are done from the building plans ,so there is no need to visit the property. Your Assessor will advise you of precisely what is needed. An EPC or Energy Performance Certificate is usually produced after the calculations are finished.

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

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


Here we have provided the most common queries asked about SAP Calculations in Birkenhead.

Exactly What Are Sap Calculations

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

How Much Do Sap Calculations Cost

If there are multiple properties with similar forms of constructions, then reductions may apply. For single properties you would then be looking in the region of £120 – £300 depending on the complexity of your construction and the dimensions. By providing the plans, you will be able to get yourself a fixed quotation.

What Is The Difference Between Sap and EPC

Before we explain the difference, this 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 properties design that’s created to display the energy effectiveness of a property. An EPC or Energy Performance Certificate is a summary report derived from the Sap calculations which produces a SAP rating from 0 to 100. This rating is expressed on the EPC as A the highest to G the lowest. It will also list recommendations that would increase the rating of your property.

There are really 2 kinds of EPCs. First is a SAP EPC which is created from building plans when all the elements of the construction are known. This would normally be required by building control to demonstrate that the dwelling complies with certain targets required by the building regulations. Building control would also have to see the SAP calculations which shows in detail whether the many components going into your property comply with the building regulations.

The 2nd type of EPC is the typical one that will be required for anyone 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, which is used where specific thermal values of, for example, the walls, roof, floors, etc, usually are not precisely known on an established property. In this situation assumed thermal values are used based on the age of your property. This sort of EPC will 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 require are the Sap calculations (which is the data behind the EPC) and the SAP EPC (which is a summary report of the Sap calculations).

Still confused, then simply contact us for further advice.

What Are As Built SAP Calculations

These are the final set of SAP calculations produced when the dwelling has actually been completed to confirm that it is compliant with Part L1A of the building regulations. Prior to the building starting, it should have had a set of “Design Sap” calculations to demonstrate that the proposed dwelling, on paper at least, will be compliant with Part L1A.



Can I Do The Sap Calculation Myself

Unfortunately this is not some thing that you can do yourself. The calculations have to be done by an On Construction Domestic Energy Assessor or OCDEA, using approved Government software programs. The Assessor must be certified under one of several accreditation schemes and is also regularly audited to maintain their accreditation.

What Info is Required 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 dwelling need Sap calculations to demonstrate compliance with Part L1A (Conservation of fuel and power in new dwellings) of the building regs.


Sap Calculations For Extensions

It’s now quite fashionable to have large bi-folding doors, sky lights and large quantities of glazing on new extensions. But with the existing building regulations the amount of glazing must be a maximum of 25percent of the floor area of the new extension. So over compensations on the thermal elements in other places within the property will have to be made to show that the CO2 emissions from the current house along with 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 need SAP calculations to find solutions and show compliance.


Sap Calculations For Conversions

For anybody who is 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 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 Birkenhead . We also cover the whole of the UK and can help 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 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 aim to provide 100% satisfaction and look forward to working with you.


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