Projects using Welsh Regulations

What is written here applies only to projects using Welsh 2022 Regulations.

You should read the NCM modelling guide for Wales and be familiar with it.

For Wales, Cardiff weather data must be used.

Notional PV area

For full details, see sections 80-81 of the National Calculation Methodology (NCM) modelling guide (for buildings other than dwellings in Wales).

The area of PV in the Notional building is equal to 10% of the building’s gross internal area, or 50% of the building’s roof area, whichever value is smaller.

NB: EDSL have been advised that for buildings with zero roof area, the area of Notional PV will be equal to 10% of the building’s gross internal area. This means that all projects will have PV in the Notional building, even those with zero roof area.