It is now being knocked into one house again. It has some great upsides: views and a good functional division per floor. Downsides: reduced width, a lot of stairs and an elaborate concrete structure that had to be kept.
In the section drawing of the house below, I proposed to the clients to make the stairs the visual vertical link in the house. Floor to ceiling windows would replace the walls. They would tie the stairwell to the house and allow for daylight. The visual zig-zag of the sides of the stairs would break up the rigidity of the vertical design.