These are few indications I’d love to follow, given that we are four: me, my wife and 2 girls:
1) A large living room also big at the entrance that I think it fits well;
2) the kitchen not in the lounge /living however close to it;
3) have 2 separate rooms for girls;
4) a double room even not big for us;
5) it is not necessary to have walk-in closets;
6) provide a storage/ laundry room;
7) In some place of the house it could also possible to include a mezzanine not very large and airy perhaps with staircase and glass parapet considered that the minimum height is 3.96 m.
N.B .: double walls are walls masters, all the others can be demolish