I have some idea's that might fix the housing problem without having to add more wards or plots:

(1) Add more options when buying a room:
- Small room: Equals 1 floor of a cottage house (no floors). Prize: 300.000 gil
- Medium room: Equals a cottage house in size (no floors). Prize 1 mil gil
- Large room: Equals a medium house in size (no floors!). Prize 7 mil gil

(2) Link the appartment system to the private FC house system so when you have a room (doesn't matter where you bought it) and you leave an fc, you should still be able to access it through the appartments (so no loss of money!).

(3) Large houses can no longer be bought for private use, and medium houses can only be bought for private use if shared with at least 1 tenant, otherwise you lose that house after 30 days.

Money wise people will feel the benefit of owning a room instead of a house, so the benefits that you pay extra for (workshop, garden, nicer interior) will become more suited for FC use.