What you need is the blessing of the building official. I could use romex in a 200,000 sqaure foot building if I meet some are exceptions in the building code.
Determining allowable height and area of a building, and therefore type of construction is a difficult thing.
The NFPA 220 won't do anything, because it isn't adopted as a building code. Even if it were, you need a lot of info before you can determine T.O.C.
