Do I still need an EPC if my building’s power supply is off the grid?

Yes, you still need an EPC. The EPC is required irrespective of the energy source (i.e. supply from the grid, independent solar PV, independent wind power etc.).

The EPC assists building owners to understand the building’s energy efficiency rating.

A benefit of the EPC may be that the energy required to power the building could be optimized resulting in a cost saving.

The different energy sources are captured on the EPC.