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

If there are a number of properties with similar forms of constructions, then special discounts may apply. But typically for a single dwelling the price will be in the area of £120 – £300. By providing the plans, it will be possible to get a fixed quote.

Before we explain the difference, 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 properties design that’s created to show the energy effectiveness of a dwelling. An EPC or Energy Performance Certificate is a summary report created 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 which would enhance the rating of the dwelling.

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

The 2nd variety of EPC is the typical one that will be required for anyone who is selling, or renting out a property. This kind of EPC uses what’s called rdSAP, which stands for Reduced Data Standard Assessment Procedure, which is used where specific thermal values of, for instance, the walls, roof, floors, etc, usually are not precisely known on an established property. In this case assumed thermal values are used according to the age of your property. This sort of EPC will be no use 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 data behind the EPC) and the SAP EPC (which is actually summary report of the Sap calculations).

If you are still perplexed, then simply contact us to get more assistance.

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. Ahead of the project starting, it ought to have had some “Design Sap” calculations to show that the proposed dwelling, in theory at least, will be compliant with Part L1A.

No, this is not something that can be done by yourself. Sap calculations have to be carried out by an On Construction Domestic Energy Assessor or OCDEA, by using approved Government software programs. The Assessor has to be certified under one of several certification schemes and is regularly audited to keep up their certification.

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)

All new dwelling need to have Sap calculations to show compliance with Part L1A (Conservation of fuel and power in new dwellings) of the building regs.

It’s now quite modern to have large bi-folding doors, sky lights and large quantities of glazing on new extensions. But under the present building regulations the amount of glazing can be no more than 25percent of the floor area of the new extension. So over compensations in the thermal elements in other parts within the property will have to be made to show that the CO2 emissions from the existing house along with the proposed extension is no worse than the existing house and an extension whose glazing is within the permitted amount judged against Part L1B of the building regulations.

You should have SAP calculations to find solutions and demonstrate compliance.

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

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. Contact us, if you are not certain if you need them.