They all use the IBC code so you just need to know what year they are using and then make sure you read thru the rules before you build.
4" sphere pass through has been in effect for over a decade, maybe two. Whether it's applicable to residential, I don't know, but I doubt it. The few houses I bid with steel in them all seem to comply with that but I think it's Architect ignorance. They've been trying to pass code compliance off to contractors and subcontractors for a very long time now. That's why I suggested he query his local building inspector.
