Here in Texas, at least where I live, each city has it's own rules. Most just follow the International Building Code, but some have their own little twists to it that you have to be aware of when getting your inspections. Outside of city limits, there is no code other then septic, and that's all done on National Law, or something like that. I haven't come across a County that had any sort of Permit process, or Code requirements. This is both good and bad. Good that we can do what we want on our land, bad that you never know what you are buying when you buy a house outside of city limits.