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Sap Calculations Woolwich

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So, Just What Are Sap Calculations?

If you are reading this article, you have probably been asked by someone, normally your building control officer, to supply sap calculations for your building project.

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



Woolwich SAP Calcs For Dwelling Change Of Use

  • Reports for Part L1B Compliance
  • Free Advice

Woolwich SAP Calcs For Overglazed Extensions

  • Carbon Emissions Reports
  • Heat Loss Calculations
  • Free Advice

Woolwich 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 method of determining the energy efficiency of buildings. The calculations are needed to illustrate that your building conforms with specific energy targets set down within the building regulations.

As a quick overview, that’s pretty much it.


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 homes
3. For a dwelling change of use, for example altering a single family home to residential flats.

The two main areas which the sap calculations will be looking at is that the carbon emissions from your property are within set tolerances and that particular components of the property, such as the walls, roof, windows and floors comply with specified thermal energy targets.

Sap computations will be done by a qualified and accredited On Construction Domestic Energy Assessor. There is no need to visit the property as all of the computations are carried out from the building drawings . An EPC or Energy Performance Certificate is usually produced after the computations are done.

Your Assessor can give you further advice in the event the calculations show your dwelling isn’t compliant, as well as tell you which would be the most effective changes to make. It could be costly if you realise at a late phase in the construction that the building is not compliant. So it’s advisable to liaise with the Assessor as early on during the project as possible, ideally before any building commences.

Should you require guidance on a project you could have in or around , or simply require a quotation, give us a call or fill in our get a quote form.


SAP Calculations in Woolwich The 10 Most Common Questions Asked.

So, Just What Are Sap Calculations?

This is probably the most common 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

This will vary considerably depending on the size and complexity of the property, however a typical price range will be between £120 – £300. There will probably be a further fee of around £50 if an EPC is required at the end of the construction. For several dwellings of similar types, then special discounts might be offered.

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

There are really two kinds of EPCs. First is a SAP EPC that is produced from building plans where all of the components of the construction are known. This would normally be required by building control to show that a property meets specific targets essential to the building regulations. Building control would must also see the SAP calculations which illustrates in detail whether all of the components going into the property comply with the building regulations.

The 2nd type of EPC is the common one that will be necessary for anyone who is marketing, or renting out a property. This sort of EPC uses what’s called rdSAP, which means Reduced Data Standard Assessment Procedure, and is used where particular thermal values of, for instance, the walls, roof, floors, etc, are not precisely known on an established property. In this situation assumed thermal values are used according to the age of the property. This kind of EPC will be no good to show compliance with any building regulations. Sometimes building control would simply ask you to get 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 actually summary report from the Sap calculations).

If you are still confused, then simply give us a call to get more advice.

What Are As Built SAP Calculations

These will be the final set of SAP calculations created when the dwelling has actually been completed to hopefully demonstrate that it is compliant with Part L1A of the building regulations. Ahead of the project starting, it ought to have had some “Design Sap” calculations to show that the planned construction, on paper at least, will be compliant with Part L1A.



Can I Do The Sap Calculation Myself

Unfortunately this is not something you can do yourself. Sap calculations need to be done by an On Construction Domestic Energy Assessor or OCDEA, by using approved Government software programs. The Assessor must be approved under one of several certification schemes and is regularly audited to keep up 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 require 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 quite modern to get large bi-folding doors, sky lights and large quantities of glazing on new extensions. However with the latest building regulations the quantity of glazing can be a maximum of 25% of the floor area of the new extension. Therefore over compensations on the thermal elements in other parts of the property will need to be made to show that the CO2 emissions from the current house along with the planned extension is no 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 will need SAP calculations to find solutions and demonstrate compliance.


Sap Calculations For Conversions

For anyone who is altering the use of a dwelling, you will need Sap calculations. {The new dwelling will have to comply with Part L1B of the building regulations.}


Do 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 list. Give us a call, if you are not sure if you need them.


Our Services

What You Can Expect From Us

Trusted & Experienced

Our Assessors are fully certified and accredited with years experience carrying Sap calculation in Woolwich . 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 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 seek to provide 100% satisfaction and look forward to working with you.


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