Yep. You can obviously upgrade to 4.5 and 6 kW (still single phase, I think), or go three phase. Single house probably do that. But I'd be surprised if the apartments had more than 3 kW installed.
This results in a big payoff for efficiency, however: high efficiency AC and heat pumps for water go a long way in increasing how much you can do on so much little power.
I mean sure, but there are certain appliances(like kettles) which really can't get any more efficient, so if you want to boil some water......3kW overall limit for the entire apartment is seriously limiting. Like, if someone is boiling water and another person uses a hair dryer, it will blow fuses?
This results in a big payoff for efficiency, however: high efficiency AC and heat pumps for water go a long way in increasing how much you can do on so much little power.