This is probably the most frequent query asked. Take a look at Andrea’s video explanation above, or read the full explanation here on the right.

The typical price range will be between £100 – £300, this is depending upon the complexity and size of the property. There may be an additional fee of approximately £50 if an Energy Performance Certificate is required at the end of the construction. Special discounts would typically be available for multiple properties especially when they are of the identical style of building.

Before we get to the differences, this is what you will require 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 computations of pre defined data set of a buildings design that’s created to display the energy effectiveness of a dwelling. EPC means 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 out a property.

There are really two types of EPCs. The first is a SAP EPC which is produced from building plans where all of the components of the building are known. This would normally be needed by building control to show that a property satisfies specified targets essential to the building regulations. Building control would also have to see the SAP calculations which shows in greater detail whether all of the elements going into the property conform to the building regulations.

The second variety of EPC is the common one that would be necessary for anybody who is 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 specific thermal values of, for instance, 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 the property. This sort of EPC will be no use to show 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 information behind the EPC) and the SAP EPC (which is actually summary report of the Sap calculations).

Still confused, then give us a call to get more advice.

These will be the finished set of SAP calculations created once the dwelling has been completed to confirm that it is compliant with Part L1A of the building regulations. Ahead of the project starting, it should have had a set of “Design Sap” calculations to show that the planned dwelling, on paper at least, will be compliant with Part L1A.

No, this is not some thing that you can do by yourself. The calculations have to be done by an On Construction Domestic Energy Assessor or OCDEA, working with approved Government software. The Assessor must be approved under one of several certification schemes and is also regularly audited to maintain 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 to have Sap calculations to prove compliance with Part L1A (Conservation of fuel and power in new dwellings) of the building regulations.

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 can be no more than 25% 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 demonstrate that the CO2 emissions from the current house along with the planned extension is no worse than the existing house and an extension where the 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 modifying the use of a dwelling, 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 is not an exhaustive checklist. Phone us, if you are not certain if you require them.