These pieces don’t actually represent an interior structure, they just serve to support the roof assembly and allow me to include the tower spirets on the corners. I used whatever floor pieces I had left over which is why it is made up of four pieces with stairwell holes. I did, however, put one of the stairwell holes in the lower right corner there intentionally–this represents the hole in the ceiling of the attic that heads out to the roof.
One Inch Square 