seperated "room"

Part of the beauty behind the concept of separate "rooms" in a house is that each unit is unique unto itself. Having separate outdoor living spaces allows you to create mini-landscape designs (each somewhat different from the rest) for each of them. Not that you shouldn't still strive for unity across your landscape design, as a whole.

Think of the structural components of outdoor living spaces in terms of their counterparts in indoor rooms: floor, walls and ceiling. Only for outdoor living spaces, the term, "structural" is used metaphorically. So much the better for you, as the "builder," since it means there's a lot less to worry about. Taking out a "wall" because you don't like your initial choice won't cause the "ceiling" to come crashing down on your head!
Furthermore, think of the materials you need to assemble the floor, wall or ceiling of an outdoor living space as the "building blocks."