[bonestamp2]

You're right. The way that some of the new cruise ships are built is that the rooms (including the bathroom) are each one long "module" that they slide into place for final assembly. This means they can be built offsite on an assembly line, and also when it comes time to renovate, they can swap them out with much less downtime for the ship.

[Symbiote]

I've seen very cheap apartments in Britain built with these "modules", and hotels in any price range all over Europe with them.

This sort of thing: https://taplanes.co.uk/