Computers and TV should be in a family room.
And fridge - Cripes they dont need more junk food.
There should not be an area that they can hide in and become recluises or get up tight when you come in.
It is your house they should feel welcome, loved and under your authority.
This idea that teens need their own space is true but it is not locking themselves away in a room by them selves. Their own space is outdoors. The house is your space and the family space.