Replacing the electricity supply to a 7-storey 1930's block of 126 flats

As the flats are existing, it should be possible to fit a data logger to the existing supply in order to obtain maximum likely load. I would allow for say 10% load growth. If the present supply is 315 amps, but routinely overloaded to say 350 amps, then consider a 400 amp supply for future needs.

If say 8 flats are empty when the data logging is done, then an extra allowance should be made for future 100% occupancy.

If gas or oil heating is used at present, then a much larger allowance for load growth should be considered in order to allow for future electric heating.

What about charging electric vehicles ? are EV chargers to be provided, if so allow 32 amps for each charger, 126 flats implies 42 on each phase. If each flat will have a 32 amp charger, then the total loading will be much less than 32 times 42. They wont all be used together ! If however a limited number of EV chargers are to be installed, then the loading per charger will be much higher, as all or almost all of these chargers are likely to be used at the same time.

As the flats are existing, it should be possible to fit a data logger to the existing supply in order to obtain maximum likely load. I would allow for say 10% load growth. If the present supply is 315 amps, but routinely overloaded to say 350 amps, then consider a 400 amp supply for future needs.

If say 8 flats are empty when the data logging is done, then an extra allowance should be made for future 100% occupancy.

If gas or oil heating is used at present, then a much larger allowance for load growth should be considered in order to allow for future electric heating.

What about charging electric vehicles ? are EV chargers to be provided, if so allow 32 amps for each charger, 126 flats implies 42 on each phase. If each flat will have a 32 amp charger, then the total loading will be much less than 32 times 42. They wont all be used together ! If however a limited number of EV chargers are to be installed, then the loading per charger will be much higher, as all or almost all of these chargers are likely to be used at the same time.