I say it on every thread of this type, and hope that those that get beyond the dreamer stage take the time to do their due diligence on the matter.
In the vast majority of the USA, in any location that has even a hint of regulation, you will probably be prevented from occupying a "tiny house" on a full time basis. Doesn't matter if the local regulations use building codes, zoning regulations, or whatever, typically it isn't going to work.
I follow a forum on the topic of cheap RV living. Many there own property in very remote areas, particularly in the southwest, often dozens of miles from civilization. Many of those folks are clear that if they are caught occupying their van, RV, unpermitted cabin, shipping container, tiny house, etc... they will be fined, or evicted. Up until very recently, I was seriously considering relocating to a beautiful, remote western mountain town. One of the deciding factors in not doing so was a recent ruling by the town council to absolutely ban anything but storing RVs on property in the town limits. Fines are levied if there are any utilities connected to the RV, or evidence of overnight occupation. Sorry, but I'm not spending my money in a town where a friend can't pull their RV in the back yard of my place, and stay a few days.
I like the concept of tiny homes, but they are like shipping container homes, straw bale homes, etc.... a concept that ends up being well done, and legally occupied by a tiny percentage of those that plan and attempt the project. Most never get beyond the dream stage, many that start never finish, and a significant percentage of the "finished product" is done very poorly. Very few end up as real impressive accomplishments. The Tiny house documentary I recently viewed on Netflix should be a wake up call. A totally clueless young guy devotes all of his efforts to building a tiny house. A year later he has a marginally done habitable dwelling, and a severely damaged relationship with his S.O. To put it in perspective, I have supervised many Habitat for Humanity projects where we built a modest home in a week, and as a professional, I can build a very nicely detailed 1300 sq. ft. home in six weeks. OTOH, the subject of the documentary painfully floundered about for an entire year to build a few dozen square feet of a poorly done tiny house. Kind of like deciding that you can't move on in life until you faithfully reproduce Columbus's fleet in 1/20th scale, using popsicle sticks........ what the hell is the point?