This is more like it--645 sq feet in Tokyo--books, plants--but no platforms for me

https://www.architecturaldigest.com/video/watch/global-small-spaces-how-an-architect-built-7-levels-into-a-2-floor-tokyo-home

need railings, safety features, lift, and safe stairs in case lift stalls.

My friend has a 5? story house in Philly with a lift.

She told me home owners are digging basements bc no space to expand sideways.