home is where you find it

The difference between formal and casual has essentially disappeared in American home design. A more accurate way of describing the different areas inside a dwelling is needed. Towers of Ilium proposes the terms "Open Spaces" and "Retreat Spaces." There is a subtle distinction between these terms and  the more common phrases "Public" and "Private." An Open Space can serve as a zone that encourages gathering, but it can also be a barrier where business is conducted. A front porch is one example, a kitchen island another. Retreat Spaces can be any room with a door--and the backyard--provided some level of separation can be created.