This is certainly quite possibly the most common question asked. Check out Andrea’s video explanation above, or read the full explanation here on the right.

If there are multiple properties with similar forms of constructions, then discounts may apply. But typically for a single property the charge would be in the region of £120 – £300. By supplying the plans, you will be able to get a fixed quotation.

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 put together to display the energy efficiency of a property. EPC stands for Energy Performance Certificate and it’s a summary statement from the SAP calculations in an straightforward document, that can also be used to sell or rent a property.

There are really two kinds of EPCs. The first is a SAP EPC which is created from building plans when all the elements of the building are known. This will normally be required by building control to demonstrate that the property complies with specified targets required by the building regulations. Building control would also need to see the SAP calculations which shows in detail whether all the components going into your property conform to the building regulations.

The 2nd type of EPC is the typical one that will be needed for anyone who is selling, or renting a property. This particular EPC uses what’s called rdSAP, which stands for Reduced Data Standard Assessment Procedure, and is used where specified thermal values of, such as, 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 your property. This kind of EPC would be no use to demonstrate compliance with any building regulations. Sometimes building control would simply ask you for the EPC, but what they would really require are the Sap calculations (which is the information behind the EPC) and the SAP EPC (which is a summary report from the Sap calculations).

If you are still perplexed, then simply call us for additional information.

These will be the final set of SAP calculations generated after the dwelling has actually been completed to confirm that it is compliant with Part L1A of the building regulations. Prior to the construction starting, it ought to have had some “Design Sap” calculations to demonstrate that the planned building, in theory at least, would be compliant with Part L1A.

No, this is not something you could do by yourself. The calculations need to be done by an On Construction Domestic Energy Assessor or OCDEA, by using approved Government program. The Assessor must be approved under one of the accreditation schemes and is also regularly audited to keep their accreditation.

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)

Every new property require Sap calculations to prove compliance with Part L1A (Conservation of fuel and power in new dwellings) of the building regs.

It’s now modern to get large bi-folding doors, sky lights and large amounts of glazing on new extensions. But with the current building regulations the quantity of glazing must be no more than 25percent of the floor area of the new extension. So over compensations in the thermal elements in other places of the property will need to be made to show that the CO2 emissions 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 permitted amount judged against Part L1B of the building regulations.

You need SAP calculations to find solutions and illustrate compliance.

If you are 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.}

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. Phone us, if you are uncertain if you require them.