0800 046 7345 [email protected]

Sap Calculations Greenwich

We undertake most sizes of non commercial projects wanting SAP calculations. All at affordable prices. Get in touch for a quotation on your job.

Get QuoteCLICK TO CALL FREE: 0800 046 7345
Air tightness testing
Water calculations

So, What Are Sap Calculations?

If you are reading this article, you have more than likely recently been requested by someone, typically your building control representative, to supply sap calculations for your building project.

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



Greenwich SAP Calcs For Dwelling Change Of Use

  • Reports for Part L1B Compliance
  • Free Advice

Greenwich SAP Calcs For Overglazed Extensions

  • Carbon Emissions Reports
  • Heat Loss Calculations
  • Free Advice

Greenwich SAP Calcs For New Builds

  • Reports for Part L1A compliance
  • Free Advice

What does SAP mean?

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 needed to show your building complies with specific energy targets set down in the building regulations.

In a short overview, that’s more or less it.


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, e.g altering a single family home to residential flats.
3. For overglazed extensions

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

The calculations are done by a qualified and approved On Construction Domestic Energy Assessor. There is not any need to visit the property because all the calculations are carried out from the building plans ,so a good set of plans are required. An EPC or Energy Performance Certificate is usually produced after the calculations are finished.

Your Assessor can provide additional guidance if the calculations show that your building isn’t compliant, as well as inform you which would be the most effective improvements to make. It could be costly if you find out at a late phase in the construction that the building isn’t compliant. So it is best to liaise with the Assessor as early on during the project as possible.

If you need guidance on a project you may have in , or simply require a quotation, call us or fill in our get a quotation form.


Sap Calculations Questions, See Whether We Have An Answer Here.

So, What Are Sap Calculations?

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

Sap Calculations, How Do They Cost

We would be pleased to offer you discounts, in particular for properties that are of the same or similar construction. For single dwellings you would be looking in the region of £120 – £300 dependant upon the complexity of your design and the dimensions. By providing the plans, it will be possible to get a fixed price quotation.

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 demonstrate the energy efficiency of a property. An EPC or Energy Performance Certificate is a overview report created from the Sap calculations that produces a SAP score from 0 to 100. This score is shown on the Energy Performance Certificate as A the highest to G the lowest. It will also list recommendations that would increase the rating of your property.

There are actually 2 types of EPCs. The first is a SAP EPC which is created from building plans where all the components of the building are known. This would normally be needed by building control to show that the property satisfies specific targets required by the building regulations. Building control would also have to see the SAP calculations which illustrates in detail whether all of the elements going into your property conform to the building regulations.

The second sort of EPC is the typical one that will be needed when you are selling, or renting out a property. This kind of EPC uses what’s called rdSAP, which is short for Reduced Data Standard Assessment Procedure, which is used where specified 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 your property. This kind of EPC will be no good to show 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 information behind the EPC) and the SAP EPC (which is a summary report of the Sap calculations).

Still confused, after that call us for additional advice.

What Are As Built SAP Calculations

These are the finished set of SAP calculations created after the building has actually been completed to hopefully demonstrate that it is compliant with Part L1A of the building regulations. Ahead of the building starting, it ought to have had some “Design Sap” calculations to show that the proposed building, in theory at least, will be compliant with Part L1A.



How To Do Sap Calculations

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

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

All new property need Sap calculations to demonstrate 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 have large bi-folding doors, sky lights and large quantities of glazing on new extensions. But with the latest building regulations the amount of glazing can be a maximum of 25% of the floor area of the new extension. So over compensations on the thermal elements in other parts 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 when compared to 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 illustrate compliance.


Sap Calculations For Conversions

For anyone who is altering the use of a building, you will require 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 list is not exhaustive. Phone us, if you are unsure if you need them.


Our Services

What You Can Expect From Us

Trusted & Experienced

Our Assessors are fully certified and accredited with several years practical experience carrying Sap calculation in Greenwich . We also cover the whole of the UK and can assist on any job nationally.

Reliable & Fully Insured

You will be assigned a dedicated Assessor who is also covered by full professional indemnity insurance 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% customer satisfaction and look forward to working with you.


Get A Quote, Or Call Us For Advice