I used these as a doorway. I first made a solid wall between room sections, placed the doorway, raised it a bit, undid the solid wall, remade the solid wall on the adjacent section (the place you had to stand to place the door), did the same thing with another door, undid the new solid wall, and now I have a doorway that is visible from both directions (because otherwise it's only visible from the direction you placed the first one).