Just FWIW in much of the rural US you are largely exempt from building codes if you are building your own primary residence. The logic being that if you built it and you live in it and it kills you, well, you only have yourself to blame. This doesn’t apply for many town and city locations, though, as there are often local zoning controls that make you build cookie cutter garbage. But the smaller and and less regulated the area, the more likely you’re allowed to build what you want so long as you do it yourself and don’t sell it to anyone else.