Small scale housing is a fad. Up in Vermont there are lots of people designing and building houses with only a few hundred square feet. But you can do better than that.
The next two pictures show a garbage truck that has been converted to a marvelous land cruising house. The pictures were sent by a blog reader.
The picture below shows someone who did it with a shipping container. It looks nice, but only for places with warm climates.
But I always thought that they go to far too much trouble and expense. A cruising boat like Tarwathie is a wonderfully functional and comfortable living unit. Libby and I are very comfortable in our 150 square feet (actually 300 square feet including the head and the v-berth). The design has been refined by choosing the best ideas from thousands of previous boats over many decades. The functional equipment, electrical, cooking, plumbing, heating, refrigeration, lights, are all suited to the application and not borrowed from conventional houses.
The smart thing to do would be to visit boat yards in the south after a major hurricane. There are lots of boats there too damaged to float, but still pristine inside. You can buy them for next to nothing. Move one of those to the lot of your choice, then dig a hole and bury it nearly to the level of the top deck (for insulation purposes.) Make connections for water, and sewer. Mount a few solar panels, and forget the electric grid. That makes much more sense than custom designiung and building a conventional, yet little, house.