From Mother Earth News article - Go Green with Low-Budget Housing : You may be surprised that I’d rate mobile homes low on the list yet write favorably of camper trailers. The difference is that camper trailers are recreational vehicles and are designed for off-grid use. Of course, some models are more like mobile homes, so you’ll have to be a little careful here, but if you can find one that’s truly intended for camping rather than as a portable retirement home, you’ll do okay.
Many already have solar power installed and are equipped with both 12-volt DC and 110-volt AC power through an inverter. Their water systems are self-contained and have sinks, toilets, and holding tanks. Most also have three-way refrigerators powered by 12-volt DC, 110-volt AC, or propane. If you’re going to use one in cold climates, you’ll need to install an alternate heat source (preferably wood heat). Their furnaces go through a lot of propane trying to keep them warm.
Paladin Press has an excellent book written by M. D. Creedmore titled Dirt Cheap Survival Retreat: One Man’s Solution. He uses a camper trailer for his survival retreat and has some great information. If you’re contemplating this option, read his book.
Note: I don’t live in the travel trailer anymore, after several years, I saved enough money to buy a larger piece of property (5 1/2 acres) and a 14′ x 48′ manufactured home - still only 648 sq.ft. I wanted to stay small to save money on heating and cooling costs – four 100 pound tanks of propane will heat this all winter.
Anyways, I would like to thank Mother Earth News for the shout out…