I call this the Chicago layout -many apartments are long and narrow. I have assumed it was to ensure access to two fire escapes. Too hazard a guess, I have seen some that might only be 15’ wide, supporting a 10x10 room with a hallway to access it.

Chicago lots are long and narrow. Typical Chicago residential lot is 25x100 or so. Street in front, alley in the back, garage if you have one is a separate building fronting the alley. Many houses are built as "two flats" or "three flats" i.e. two or three houses stacked on top of each other.

I was a bit surprised by this, but, yea, pulled up random part of chicago and it's basically exasctly as described.

https://www.google.com/maps/place/Chicago,+IL/@41.7332309,-8...

This is really common in and around Boston too. The architectural style is from the area and we cal them three deckers (in Boston) or triple deckers (everywhere else). Lot size is probably similar, and they’re still highly valued (if kept up) to this day because of their construction and other benefits. I live in one now and others around me go for 750k+

https://www.dotnews.com/columns/2014/glorious-three-decker