We all remember these from our Grandparents or Great Grandparents. They were 800-1000 sf, rooms flowed around a central wall and there were rarely any halls. Every square inch was used and accounted for. The nook on L-Shaped houses today actually cuts off a lot of usable space for the materials used. If you flipped and inverted the L-Shaped wall, you could enclose the space that is cut off with the same amount of wall material. This leaves you the option of reducing the materials and labor to achieve the square footage that you want - OR - using the same amount of materials, you can achieve more usable space. Units are also more efficient if nested into multi-family housing.
Yes, I know. My wife likes the nooks from offsetting a room in a house. It adds style. Is an aesthetic thing that we've gotten used to seeing. We finally compromised when building our house and built a rectangle shaped building. I just wanted to point out that you lose efficiency of materials as you deviate from a square. More building materials and labor for less square footage.