I am trying in HD Pro to generate a stairwell for a stairway leading from the first floor to the second floor of a two-story house. The Auto Stairwell tool doesn't show up in the toolbar, which I read in Help is a sign that there is no living space above it. But, as far as I can tell, there IS living space above. I also tried to generate the stairwell manually bit without success. I put a railing around the area on the second floor and created an open below. From the second floor, you could see the ground through the opening and from the first floor you could see the sky through it.
Can someone help me understand, first, why the Auto Stairwell tool doesn't appear on the toolbar?
House plan-existing-v2 save6.plan