This is 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.

We will be pleased to provide discount rates, in particular for properties that are of the same or very similar construction. But typically for a single property the charge will be in the area of £120 – £300. By providing the plans, you will be able to get yourself a fixed quote.

Before we explain the difference, here is what you will require 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 computations of pre defined data set of a properties design that’s created to demonstrate the energy performance of a dwelling. EPC is short for Energy Performance Certificate and it’s a summary report of the SAP calculations in an straightforward document, which can also be used to sell or rent a property.

There are really 2 types of EPCs. The first is a SAP EPC which is created from building plans where all the elements of the construction are known. This would normally be needed by building control to show that the property complies with specified targets required by the building regulations. Building control would must also see the SAP calculations which illustrates in greater detail whether all of the elements going into the property comply with the building regulations.

The second sort of EPC is the common one that will be needed when you are marketing, or renting 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 example, the walls, roof, floors, etc, are not precisely known on an established property. In this case assumed thermal values are used based on the age of the property. This kind of EPC will be no use to show compliance with any building regulations. Sometimes building control would simply ask you for the EPC, however what they would really need are the Sap calculations (which is the data behind the EPC) and the SAP EPC (which is a summary report of the Sap calculations).

Still confused, then simply phone us for further assistance.

These are the finished set of SAP calculations created once the dwelling has been completed to hopefully demonstrate that it is compliant with Part L1A of the building regulations. Ahead of the construction 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.

Unfortunately this is not some thing you could do yourself. The calculations must be done by an On Construction Domestic Energy Assessor or OCDEA, working with approved Government computer software. The Assessor needs to be approved under one of several certification schemes and is 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)

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

It’s now modern to get large bi-folding doors, sky lights and large amounts of glazing on new extensions. However under the present building regulations the amount of glazing must be a maximum of 25percent 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 from the current house and the planned extension is no worse when compared to the existing house and an extension whose glazing is within the permitted amount judged against Part L1B of the building regulations.

You will need SAP calculations to find solutions and demonstrate compliance.

When 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 list is not exhaustive. If you’re uncertain whether you need them, then phone us.