Good point Wolverine, I didn't realize. I figured brown stones were different [[?). Although, I do wonder if the first two in my list were parts of row house blocks of some sort, at one point. Today, maybe they are the last ones left?

Quote Originally Posted by wolverine View Post
Traditionally, two walls. Each house could stand on its own if its neighbor was demolished. The type of stuff you see going up nowadays around Detroit either has cmu block fire separation or a heavy stud wall with a ton of gypsum board to meet life safety requirements. In those cases it's a single wall. After all these, buildings are trying to emulate old fashioned towne house architecture.

If there was a gap between two brick walls, it was never much of a big deal back then....at least now-a-days we know more. Walls weren't all that high, and yes at times the result of settling would cause one home to possibly lean against another. I've seen demolitions where they deliberately left the exterior wall of a demolished home remaining to support another.