Documentary Evidence

If a thermal element of a property has had its energy performance improved since it was originally built, and if that improvement cannot be visually confirmed during an assessment then some form of Documentary Evidence is required in order for that improvement to be included in an EPC assessment.

Examples of this include insulation that has been added in a sloping roof or a flat roof or in a floor.

This can apply if you have had any work carried out on your property to improve its energy performance and have specific documentary evidence of U values for walls, windows etc from the supplier or developer.

If this is the case, then your energy assessor can use these figures to override the assumed values in RDSAP and hopefully improve your EPC rating as a result.

It can also apply if you have a property that is quite new, which had a full SAP EPC carried out 'on construction'. If the developer had the property built with significantly better energy performance than that required by building regulations in place at the time, then that advantage will be lost after 10 years when a new EPC assessment is carried out using RDSAP rather than SAP.

This is because RDSAP assumes the minimum thermal performance used by building regs at the time.

If you can get hold of that original engineering information that would have been supplied to the On-Construction energy assessor for the original SAP EPC then your RDSP energy assessor will be able to use that information to override the U values in the RDSAP assessment 10 years afterwards and improve your EPC rating.

The likelihood of you getting hold of that engineering information is slim, and I have not come across a client yet who has had it available. That however does not stop you from being the first one.

Click here to return to our 'Improve Your EPC' main page, and see if there is another way you could improve your EPC rating.