This is Canary. It has an Open first Floor.
The intent of the open floors was for players to add walls as they liked. Some fit kinda weird but you can wall off sections as you prefer. That is why they built it out of basic stone, so you can craft stone walls and add them in.
The circled walls were added by me. This is an open floor normally.
Same Floor without walls.
You could decorate like me and just clutter up the large open areas.