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Sap Calculations Greenwich

Sap computations for new build, dwelling change of use, or overglazed extensions that have more than 25% glazing. All at reasonable prices. Contact us to get a quote on your job.

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Exactly What Are Sap Calculations

Have building control, or your architect asked that you get sap computations. Why do you need them and what exactly are sap calculations anyway? Then read on.

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



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 stands for Standard Assessment Procedure and it is the UK government’s means of calculating the energy efficiency of buildings. The calculations are necessary to illustrate your building complies with certain energy targets set down in the building regulations.

In a quick summary, that’s essentially it.


When Are SAP Calculations Needed?

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

1. For all newly built dwellings
2. For a dwelling that’s changed its use, for example altering a single family home to residential flats.
3. For extensions that have more than 25% glazing

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

Sap computations will be carried out by a professional and approved On Construction Domestic Energy Assessoror OCDEA for short. There is not any need to visit the property because all of the computations are carried out from the building drawings ,so a good set of plans are very important. An EPC or Energy Performance Certificate is usually produced after the computations are finished.

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

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


Sap Calculations Questions, Check If We Have The Answer Listed here.

Exactly What Are Sap Calculations

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

What Is The Cost Of Sap Calculations

The typical cost range is between £100 – £300, this can be depending on the difficulty and size of the property. There may be an additional charge of approximately £50 if an Energy Performance Certificate is called for at the end of the build. Reductions would typically be available for multiple properties especially if they are of the identical type of structure.

What’s The Difference Between Sap and EPC

Before we explain the difference, this is what you will require 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 computations of pre defined data set of a properties design that’s created to demonstrate the energy effectiveness of a building. An EPC or Energy Performance Certificate is a summary report produced by the Sap calculations which produces a SAP score from 0 to 100. This score is expressed on the Energy Performance Certificate as A the highest to G the lowest. It will also list suggestions that would increase the rating of your property.

There are really two kinds of EPCs. The first is a SAP EPC that is created from building plans where all of the components of the building are known. This would normally be needed by building control to show that the property satisfies certain targets essential to the building regulations. Building control would also have to see the SAP calculations which shows in greater detail whether the many elements going into the property conform to the building regulations.

The second type of EPC is the regular one that would be necessary if you are marketing, or renting out a property. This sort of EPC uses what’s called rdSAP, which is short for Reduced Data Standard Assessment Procedure, and is used where specific 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 based on the age of the property. This sort of EPC will be no good to show compliance with any building regulations. Sometimes building control would simply ask you to get an EPC, but what they would really need are the Sap calculations (which is the data behind the EPC) and the SAP EPC (which is actually summary report from the Sap calculations).

If you are still perplexed, then phone us for further advice.

What Are As Built SAP Calculations

These are the finished set of SAP calculations produced once the dwelling has actually been completed to hopefully demonstrate that it is compliant with Part L1A of the building regulations. Prior to the project starting, it ought to have had a set of “Design Sap” calculations to show that the planned construction, in theory at least, will be compliant with Part L1A.



Can I Do The Sap Calculation Myself

No, this is not some thing that you can do yourself. Sap calculations need to be carried out by an On Construction Domestic Energy Assessor or OCDEA, working with approved Government software programs. The Assessor needs to be certified under one of the certification schemes and is also regularly audited to maintain their qualification.

What Information 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 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 modern to get large bi-folding doors, sky lights and large quantities of glazing on new extensions. But with the present building regulations the quantity of glazing can be a maximum of 25% of the floor area of the new extension. So over compensations in the thermal elements in other places of the property will have to be made to show that the CO2 emissions coming from the current house along with the planned extension is not any worse when compared to the existing house and an extension where the 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

For anybody who is altering the use of a dwelling, you will require 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 checklist is not exhaustive. If you’re not sure 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 Greenwich . We also cover the whole of the UK and can help on any job nationally.

Reliable & Fully Insured

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


Get A Quote, Or Call Us For Advice