I really don't understand how the comon spaces work and its consuming me
Just hover them, you'll see their scoring condition. They all score 2 points for each room of a specific type adjacent to them.
- Laundry scores 2 points per adjacent Bedroom.
- Diner Room scores 2 points per adjacent Bathroom.
- Game Room scores 2 points per adjacent Closest.
- Kitchen scores 2 points per adjacent Common Room.
- Living Room scores 2 points per adjacent doorway.