The isolator (yellow) should be down by the PV isolator (red) where cupboard will be built (below the blue dotted line). You can see how plaster board is mounted on battons to allow sufficient cable-run behind it.
Once the wall/cupboards are finished if you weren't familiar with it then...
Hi, We are having an extension where the consumer unit is mounted up high near the ceiling, with the meter and the solar PV isolator etc all down low in a cupboard, with a false wall hiding all the cabling between them.
The electrician has gone off spec and run the tails from the meter out a...