I'd think those codes depend on the location.
For example in Cook and DuPage Counties in Illinois (Chicago) you need to run all electrical wire in conduit. 1 County further west you can use romex.
I'd think when it comes to heating-there would be some rules.
But I just need to shut up because I need to build some shelves myself and ideally a fairly basic workbench. (something to clamp my grainmill too)