3/6 of the houses I spent a lot of time in as a kid had finished basements. Anecdotally, finished basements are practically required if there is any sort of hi

3/6 of the houses I spent a lot of time in as a kid had finished basements. Anecdotally, finished basements are practically required if there is any sort of hill, which fairly common in the west, whereas they're likely to be absent for houses built on the floodplain.