Looking more into building and dwelling and I came upon this paper by one Philip Steadman: Why are most buildings rectangular? It’s a great architectural theory piece that explores a variety of general floor-plan layouts and the structures that go with them. It’s worth a look for the variety of floor plans and layouts illustrated in the paper alone.
In summary there are host of reasons why rectangular structures are so prolific and three main points are explored including the use of instruments used by building designers (you have rectangular implements it’s easy to design rectangular buildings), cultural attachments to mathematical concepts and spaces (has western geometry influenced out capacity to design enclosed space?), Is there a deeper psychological tie to how spaces are arranged?
In the piece the author demonstrates how in many places and times the basic structure is often a single space and that single space will often be circular in more primitive societies. It is also noted however that some single-spaces have a basic rectangular design that will incorporate non-rectangular extensions as the structure is expanded (copula, towers, apses). Historians have explored the issue and it is noted that less sedentary less well established people tend to build circular dwellings but as a people tend to be more sedentary a rectangular design dominates architecture.
It’s all pretty interesting stuff to me and useful stuff to consider when building an RPG campaign where the GM doesn’t want the players bumping into the same architecture again and again. Take the time to give the paper a read as I mentioned above it’s worth it for some of the illustrations alone.