Several have mentioned The required 120v circuits include 2 small appliances for kitchen counters, 1 for the laundry 1 for the bathroom(s). But I think the main problem you run into is 210.6.A Occupancy limits 120v nominal between conductors for luminaries and cord and plug connected loads 1440 nominal or less. This means all those 240v devices other countries use would not be code compliant in the US with regard to lighting and appliances most are under 1500w.