From what I can tell, our house originally had a breezeway that connected the main bit to the carport and workrooms. Sometime in the early 60s this breezeway was turned into an extra room and the workrooms were reconfigured to serve as additional bathroom and bedroom space.

Maybe the unfinished half-wall in the carport was put up during this time. We are learning, as we brainstorm how to deal with the open cinder block cubbies, how previous owners used the wall.