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

If there are several properties with similar types of constructions, then reductions may apply. But typically for a single property the charge would be in the area of £120 – £300. By supplying the plans, you will be able to get a fixed price quote.

Before we get to the differences, 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 performance of a building. EPC means Energy Performance Certificate and it’s a summary report of the SAP calculations in an straightforward document, that could also be used to sell or rent out a property.

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

The second variety of EPC is the standard one that would be required when you are selling, or renting a property. This type of EPC uses what’s called rdSAP, which means 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 existing property. In this instance assumed thermal values are used based on 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 to get an EPC, however what they would really require 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 contact us for further assistance.

These are the finished set of SAP calculations generated when the building has actually been completed to show that it is compliant with Part L1A of the building regulations. Ahead of the project starting, it should have had some “Design Sap” calculations to demonstrate that the planned construction, on paper at least, would be compliant with Part L1A.

No, this is not some thing you could do yourself. Sap calculations need to be done by an On Construction Domestic Energy Assessor or OCDEA, by using approved Government computer software. The Assessor has to be certified under one of several certification schemes and is regularly audited to keep up 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 need Sap calculations to show compliance with Part L1A (Conservation of fuel and power in new dwellings) of the building regs.

It’s now quite fashionable to get large bi-folding doors, sky lights and large amounts of glazing on new extensions. However under the latest building regulations the quantity of glazing must be no more than 25percent of the floor area of the new extension. So over compensations on the thermal elements in other places of the property will need 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 will need SAP calculations to find solutions and illustrate compliance.

If you are 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 is not an exhaustive checklist. Contact us, if you are uncertain if you require them.