from what I have encountered in my endeavors with the legality of these things... at least in N.C. ... you have to have a license plate on it. That means working with the DMV inspector. You will have a MUCH easier time with them than with the building code guys, and that is where I would start. Search out the laws for building your own camper trailer, they are there. Most of those DMV inspectors are folks who come out to inspect people's hot rods and such, they're usually pretty cool and are impressed by neat things, this is rarely the case with building code inspectors. After you find out the laws from the DMV about building your own camper trailer, contact the inspector personally and ask them. Law or not law, they have the final say so you're going to want to adhere to their suggestions, you may be able to coax them to allow certain things, but other things are definitely not going to fly. One issue, is how to keep the roof on while trucking down the road at 70 mph? how about keeping it from rattling apart while going down poor roads? The inspector is going to want to know these things, if you're very lucky they will have suggestions for you. Using screws and liberal amounts of serious adhesive (subfloor adhesive is the best I've ever found) will keep it together as best as possible. As far as trailer selection goes, I would stay well clear of any light duty trailers and go straight for heavy duty equipment trailers, I have a very nice 20 ft. medium duty trailer, but it flexes so much that it would literally tear a tiny house apart, you need something very rigid and unyielding, but that means it's heavier (unless you engineer it yourself). Regarding the weight issue, all states are different. Here in N.C. you can put 24,000 pounds on the road without a special license. That means 24,000 pounds ON THE ROAD, doesn't matter how much the vehicle weighs or how much the trailer weighs, as long as the vehicle has the appropriate road taxes paid (and obviously can handle the weight) then you're ok.
I would NOT let on that this is going to be something for you to LIVE in, but a cool fun project
that you want to build, they'll be much more open to that... If your state won't allow you to do this, fine, get a friend in a state that does and build it there, get it licensed there. Just KEEP A TAG ON IT... then all you have to do is with the tiny house NO WHERE TO BE SEEN, go and get the proper permits for an RV site on your land. Then, move the tiny house on and KEEP THOSE TAGS CURRENT...
as far as I know, that is the only way to keep out of the mess of trying to get a building code department to allow this, that is by circumventing them... Most places have a minimum allowable square footage for a home. Almost everywhere will want you to have real concrete
footers around the home (that adds alot
If you have a license plate on it, you'll have to pay taxes for an RV, but that's it. After you have a legit RV pad on your land, and a home-made RV with tags, there isn't much that can be done aside from ordinances that do not allow RVs...
the next step is to not flaunt it! hide your cool little house behind something, you do not want to draw attention as that will always end badly for folks who are going against the "normal" way of things.
Good luck! As you can tell, I am starting this process myself. I respect folks who fight for change, but right now I'm taking the best route I can and working within the loopholes of the law, the trick is not to let anyone know that's what you're doing! As far as anyone should know, you're just building a cool little project for yourself to take camping from time to time...
Oh, and regarding old mobile homes, most states do NOT allow people to use these as a base for building a trailer of any type... At least not legally and openly.
The agency you're going to have issues with will most likely NOT be the code enforcement (unless a bad neighbor calls them on you), but would be the county tax assessors... They send folks out every couple of years to check up on EVERYONE, and they are the ones that are most likely to catch you. All the municipalities these days are cash strapped (or just greedy, hard to tell the difference) and they want their money! That's why KEEPING THOSE TAGS CURRENT is of utmost importance, by keeping tags current, you are paying taxes on it and they will most likely be appeased by that.
lastly, one thing that I haven't found any laws regarding YET and may end up experimenting with (at my own peril possibly) is with our WWOOF
shack, we have a factory built camper trailer as our WWOOFer
apartment, but I really hate how it looks here, so I'm going to slap some siding and a slightly conventional roof on it. True, you still have a very poorly built RV under the skin, but it will look nice
I have no idea how this is going to work out for me, but best thing to do is keep my mouth shut and not ask permission!
after all that... check your local
building codes, find out if they DO have a minimum square footage... If you CAN work with their rules then by far, that is the absolute best way, I have only shared the way that I have chosen to go as the local code guys here are ridiculous to deal with and they have the right to "interpret" the code as they see fit, works great if they're in a good mood and are nice guys, but they aren't, i've had nothing but grief out of them. also, all of our plans
for "tiny houses" are not going to be for us to live in, but will be for farm volunteers and guests to stay in, so our needs would not match the needs of someone who is building something for longer term living... The best solution I've found was not to go in there with some plans
I drew up, but to go in there and ask "what can I do, how small can I build", get some answers and then think about your best course
of action. I hope that you have a better experience than I did!