I’m not seeing anything under the topic…is this just a general discussion, or an error in the system?
In any case, I would say that of the things that separate sculpture from structure, doors and windows are some of the most important. A room without windows or doors is a cube–it serves no purpose. Add a door, and then it becomes a room, a partition of space. Windows aren’t necessary, strictly speaking, but to make it a place where people would like to be and live, they are an important addition.
Likewise, how, where, and what kind of windows and doors make a huge difference on the feel of a place. There are so many different styles that there really is something for any given situation.
That’s all I really have to say about that for now.