Perhaps if you defined the characteristics of the "sitting room" it would help.
We have a "Living Room", which has a fireplace, and the dogs aren't allowed in there, so it's a place to relax and have a nice chat with company. Also, the kids aren't allowed to play in there or bring any food in there. It tends to stay neat and orderly for the most part, except when housing the Christmas Tree and subsequent unwrappings as it did not so long ago.
We also have a "Family Room", which contains the TV and is where we tend to hang out as a family for TV, board games, and other fun stuff. It tends to stay a little messier with some toys, the baby's jumper, etc.