No. of Recommendations: 2
So, they'll end up having to tear it down as unsafe.
Not necessarily. There're tons of details in a building code that are there to make a building very safe, but that doesn't mean that deviating from the code makes it unsafe. I mean, probably 90-95% of the buildings in most major metros - especially in older cities - were built under prior versions of building codes and don't currently comply with the most current versions of building codes. But we don't go around tearing them down.
Given that we have no idea what aspects of the code that architect thought the plans didn't comply with, or whether those deviations survived into the current version of the ballroom plans, I wouldn't assume that the building will be unsafe enough that it would need to be torn down.