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

We would be pleased to offer you discounts, in particular for properties that are of the same or similar construction. For single dwellings you would be looking in the region of £120 – £300 dependant upon the complexity of your design and the dimensions. By providing the plans, it will be possible to get a fixed price quotation.

Before we get to the differences, 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 buildings design that’s put together to demonstrate the energy efficiency of a property. An EPC or Energy Performance Certificate is a overview report created from the Sap calculations that produces a SAP score from 0 to 100. This score is shown on the Energy Performance Certificate as A the highest to G the lowest. It will also list recommendations that would increase the rating of your property.

There are actually 2 types of EPCs. The first is a SAP EPC which is created from building plans where all the components of the building are known. This would normally be needed by building control to show that the property satisfies specific targets required by the building regulations. Building control would also have to see the SAP calculations which illustrates in detail whether all of the elements going into your property conform to the building regulations.

The second sort of EPC is the typical one that will be needed when you are selling, or renting out 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 instance, the walls, roof, floors, etc, usually are not precisely known on an established property. In this instance assumed thermal values are used according to the age of your property. This kind of EPC will be no good 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 information behind the EPC) and the SAP EPC (which is a summary report of the Sap calculations).

Still confused, after that call us for additional advice.

These are the finished set of SAP calculations created after the building has actually been completed to hopefully demonstrate that it is compliant with Part L1A of the building regulations. Ahead of the building starting, it ought to have had some “Design Sap” calculations to show that the proposed building, in theory at least, will be compliant with Part L1A.

No, this is not some thing you could do yourself. The calculations need to be carried out by an On Construction Domestic Energy Assessor or OCDEA, using approved Government program. The Assessor needs to be approved under one of several accreditation schemes and is regularly audited to keep 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 property need Sap calculations to demonstrate compliance with Part L1A (Conservation of fuel and power in new dwellings) of the building regulations.

It’s now quite trendy to have large bi-folding doors, sky lights and large quantities of glazing on new extensions. But with the latest building regulations the amount of glazing can be a maximum of 25% of the floor area of the new extension. So over compensations on the thermal elements in other parts within the property will have to be made to demonstrate that the CO2 emissions coming from the current house and the proposed extension is no 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 will require SAP calculations to find solutions and illustrate compliance.

For anyone who is altering the use of a building, you will require 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. Phone us, if you are unsure if you need them.