They're comparable to any other type of construction. Obviously, if you leave a door open, whether it's built out of wood, out of concrete, or out of steel, you're still going to get smoke in that stairwell. The structure itself is intact and will perform as well as any other structure. Other factors such as doors opening and people piercing holes in them, we can't control.
On March 20th, 2018. See this statement in context.