In many cities, the second staircase is used as an amenity. Chicago is chock-full of old houses converted to three-flats. Most of those flats have large balconies on the back... with a staircase. These balconies provide fresh air and nice views at a price point where both of those things are otherwise impossible to find. So yes, my counterpoint is "but I like the second staircase." But, I really do - a lot of people…
>Most of those flats have large balconies on the back... with a staircase. It sounds like you're describing an external staircase - loosely speaking a fire escape. I could be wrong though, I'm not sure. The article was discussing the requirement for _fully enclosed_ internal staircases, which is different.
These also have the added bonus of being generally a nicer staircase than the one that's actually built into the house. The interior, retrofitted staircases tend to be narrow with lots of awkward, angled steps.