[Ichthypresbyter]

I live in one of the earliest post-WW2 planned suburbs (in Maryland). Many of the houses here are two-storey and were built as such, but with the second floor unfinished (in other words just an attic with no interior walls, decoration, etc) until the owners needed the space and had the money.

On some other streets, people have added a floor to what were originally built as one-level homes.