Most municipalities use the NEC with some additions to the code they have incorporated into their own code/permits. Most of these changes are for structures that contain human occupancy, like smoke detectors,arc fault and GFCI, and so on. It's code where I live that an attached garage must have 5/8" drywall at least on the common or connecting wall to the home,mostly for fire code,just like a fire rated door connecting your garage to your home.
I can only speak from my experience, but where I live I have obtained a "home owners electrical license". Which allows me to perform all the electrical work ( I still had to take a electrician's test approved by the city and pay a yearly license fee), which still needs to be inspected by the city's electrical inspector. I would recommend anyone to keep a copy of the current NEC code book on their shelf. They're not that expensive for a new one and the code does not usually make big changes from year to year, so picking up a used copy within five years of the current date is a cost effective way to go. Most fires are electrical related, why not play it safe? If I ever have a question, our city electrical inspector is available to answer questions in person or via telephone at regular set times during the day. And, thats what I suggest you start with a call to your local municipality/building dept., and ask your questions? After all, they are going to issue the permit and inspect the work.
BTW, there's a learning curve to understanding the NEC book. IMHO the book is written 20% electrical and 80% lawyer speak. But once you get used to it, you can find your answer quite easily.