Today I learned about the cube houses in Rotterdam!
https://en.wikipedia.org/wiki/Cube_house
@weirdestate visited these a couple years ago. They're iconic, but in terms of the actual space you get the footprint:usable space ratio is just terrible.
You've got a really awkward stairway for the entrance, the lounge area at the top is like a greenhouse, super hot and of course no air conditioning to manage that. These kind of suit a single person, perhaps surviving for a bit when a partner moves in.