Diggin' these designs, 
As I came to find out myself, though, the structure you ultimately end up with is largely dependent on navigating your way through (and in some cases, around entirely) the government building and zoning codes you mention above. For example, it was long held in the "Tiny House" community that simply putting a home on wheels was a way to get around draconian regulations.
But that's simply not the case everywhere, all the time. In my own experience, I actually found that there were more hurdles in living in what my Township deemed a "Recreational Vehicle" than there were if I built the same home without wheels, what they called a "Hunting Cabin" (any structure below 500 square feet used for living).
The property tax difference in building a State-sanctioned "dwelling" vs. a "tiny house" are drastically different, too. (The latter is much lower than the former).
It's tough to keep straight. I'm planning on writing a book "Open Sourcing" the methods to deal with such government codes and how best for people to get around them, as the attempts at doing so thus far simply aren't satisfactory or thorough enough to be useful.
Consider all these factors while you design your home, as it's a major disappointment to be on the cusp of construction and have to go back to Square One entirely (been there, done that - learn from such mistakes!)
Hopefully it will help people like yourself in the future and can't wait to see what other tiny home stuff you post going forward.
RE: The Tiny House Movement: How I want to collaborate