I am able to only guess from comments in this article There are tons of stairs to phases that don't adjust to the IBC, and possibly a lot more in worship buildings. Theatre consultants, like myself, would at times get around this by not together with stairs to phase in https://messiahgfdav.ltfblog.com/36323428/the-smart-trick-of-seecontainer-kaufen-that-no-one-is-discussing