Glad to hear it. I tried to replicate it too but I wasn't successful.
The closed apartments doors are my "clever" way of managing random procedural generation with a still limited pool of rooms (more will be added later). Basically, the more you progress in the game, the less chance there's to have a closed room. It's a way to limit the number of available room at the start of the game so you don't immediately see all the rooms. You can see it as a representation of the rooms you've yet to see.