SAP For Dwelling Change Of Use

Sap For Dwelling Conversions

Listed below are some examples of typical dwelling change of use.

• Building a barn conversion
• Converting a house into several flats or visa versa
• Converting an industrial building into flats or other residential dwellings
• Various dwellings transformed into a reduced number of dwellings

All the above illustrations will need the proposed conversion to conform to Part L1B of the building regulations. Part L1B mandates that minimum thermal elements must be achieved for the walls, roof, floors and glazing. The thermal values are shown in u values. A u-value is simply a calculation of the rate that heat is lost through a particular item, the lower the value, the more effective the heat retention.

A Sap EPC will also be needed for building control, if the project was a dwelling change of use.

For extensions only, an EPC is generally not needed. However, in certain circumstances building control may ask for an EPC and the Sap calculations, such as if the extension is over a certain size. Sap calculations may also be required for certain major renovations.

Building Regs – What’s Required

It’s advisable to have the Sap calculations carried out before commencing the building so that you know the building is going to be compliant on completion. We get many requests to do Sap calculations on buildings that have been finished. At this stage it’s simply pot luck whether the building will comply or not and any rectifications on the home could possibly be frustrating and costly.

All the calculations are done from the building plans, therefore a site visit is not required. To be able to carry out the Sap calculations the following items are required:

• Floor Plans to include sections and elevations of both the main house and the extension.
• 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)

Listed here are the targets that the thermal elements must reach when converting a property. New elements must reach the figures in Table 1 and existing elements targets are in Table 2 if they are worse that that those in the threshold column.

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