Where are those codes written in law? Just wondering...would like to cite them....
Generally they become local regulations at the county and municipal level, once those governing bodies vote them in,...which they are scripted to advocate.
Technically, federal government and major agencies now design and construct to International Building Code, and the 10 or so other adjunct codes all interlock together.
Reviewing how they are written, they follow the European model of codification, which tends to dictate the actual method of design calculations made during the design process, resulting in everything appearing to be ‘canned’ or off the shelf design.