Hello.

I am illustrator and I make floorplans of houses from television series and movies and I would like to make a plan of the house of this series.
For this I have done a little search for images and I have a big question:
Why does a spiral staircase appear in the first seasons (used as a library) and a different staircase appears in the latter ones?
Does the house have two floors?
What is upstairs?

Thanks.