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.

We will be pleased to offer discount rates, in particular for properties which are of the same or similar construction. But typically for a single property the charge will be in the region of £120 – £300. By supplying the plans, you will be able to get a fixed price quotation.

Before we explain the difference, this 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 efficiency of a building. An EPC or Energy Performance Certificate is a summary report created from 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 recommendations which would increase the rating of your dwelling.

There are actually 2 types of EPCs. The first is a SAP EPC that is created from building plans where all of the components of the construction are known. This would normally be required by building control to demonstrate that the property meets specified targets essential to the building regulations. Building control would also need to see the SAP calculations which illustrates in greater detail whether the many elements going into your property conform to the building regulations.

The 2nd type of EPC is the common one that will be required if you are selling, 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 specific thermal values of, for example, the walls, roof, floors, etc, are not precisely known on an existing property. In this situation assumed thermal values are used based on the age of your property. This type of EPC will be no use to demonstrate compliance with any building regulations. Sometimes building control would simply ask you for an EPC, but 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 from the Sap calculations).

Still confused, then simply phone us to get more assistance.

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

Unfortunately this is not some thing that you can do yourself. Sap calculations must be done by an On Construction Domestic Energy Assessor or OCDEA, using approved Government software programs. The Assessor must be certified under one of several accreditation schemes and is also regularly audited to keep up their qualification.

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

It’s now quite modern to get large bi-folding doors, sky lights and large quantities of glazing on new extensions. However under the latest building regulations the amount of glazing must be a maximum of 25percent of the floor area of the new extension. Therefore over compensations on the thermal elements in other parts of the property will have to be made to show the CO2 emissions coming from the existing house along with the planned extension is no worse when compared to the existing house and an extension whose glazing is within the allowed amount judged against Part L1B of the building regulations.

You need SAP calculations to find solutions and illustrate compliance.

For anybody 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.}

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. If you’re uncertain whether you need them, then simply give us a call.