A "tiny house" is a fine idea, as long as you don't intend to use it the way people use RVs. If you plan to build it in a permanent location, and NOT make it mobile at all, fine. But if you intend to put it on a trailer frame, you are reinventing the wheel, and the designs I've seen make no sense in lieu of a real RV. RVs have decades of experience behind them; tiny houses have maybe 5 years, and are sorely lacking in many ways. Yeah, yeah, I know, greatest thing since sliced bread, better invention than peanut butter to listen to the advocates. For the money, I'd go with a regular RV, however.