House Design - Privacy
Balancing togetherness with privacy.
Most humans are naturally social beings and we like to be surrounded by other people, particularly other family members. From time to time though we all need a bit of space. Getting this balance right is an important function of a well designed floor plan. (The big other factor here is having walls with good sound proofing characteristics. Concrete walls with concrete floors definitely help here.)
Hub rooms and private rooms
The best idea is to designate some rooms as hub rooms and some as private rooms. There will naturally be more hub rooms on the main floor compared with the bedroom floor. The kitchen is a good social gathering place and so is a natural hub room. A children's communal play room or landing area upstairs is another good hub, but bedrooms need to be private rooms. If things are designed right, people should feel awkward about going into someone else bedroom, but not think twice about going into a hub room. Everyone living in a house should feel that they have their own designated space where they can occasionally retreat to without being bothered by others.
Accommodating territorial family members
Even within a room that is primarily a hub room such as the family living room, there may be some unwritten rules about who owns what territory within the room. I tend to always sit on the same sofa and I have carefully arranged my stuff such as PCs, other gadgets, and papers etc around me. Other family members know that they should in preference sit in a different chair. Some people are more territorial than others. Obviously if everyone in the household is territorial in the family living room then that is going to mean you need a bigger family living room. Even assuming you can afford a bigger family living room, it's actually quite hard to do because then you run into the problem of everyone being too far away from the TV for comfortable viewing. As with everything else in house floor plan design, it comes down to making the right compromises.