I just looked again at the plans. There is a staircase in the front of the house.
The second one is the spiral staircase in the kitchen area.
Yes there are 2 staircases. They both go to the basement. One is opposite the breakfast area, as I indicated; one is in the rear of the kitchen.
In your original posting you indicated there was a stairway in the foyer, which there is not.
In any event, I assume the furnace man saw nothing unusual in his trip to and from the basement.
View attachment 274389
Barry and Honey Sherman sued builders of North York home
I vaguely recall noticing a better photo somewhere but isn’t that a glimpse of the spiral staircase leading from the main foyer to the 2nd level on the right side of this photo?
I’m sure We are all talking about the same staircase. I don’t classify it as being in the foyer since the floor plan has an area clearly identified as “foyer” and there is no staircase in the foyer. There is a staircase opposite the breakfast room which is the one shown in the picture.