Nonsense. It is perfectly possible to upgrade. Just expensive.every building's electrical panel has a finite load capacity.
Best case: put in a bigger transformer (if there is room and a big enough service on the street)
Worst case:
- run a new line to the site
- dig a new transformer vault
- run new wiring to the units
Granted:
"Best case" will cost probably $20K to $40K
"Worst case" will cost probably $40K to $60K + a lot per unit depending on the distance