Tiny homes : simple shelter : scaling back in the 21st century / Lloyd Kahn.

Enhanced descriptions from Syndetics:

There's a grassroots movement in tiny homes these days. The real estate collapse, the economic downturn, burning out on 12-hour workdays - many people are rethinking their ideas about shelter - seeking an alternative to high rents, or a lifelong mortgage debt to a bank on an overpriced home. Homes on land, homes on wheels, homes on the road, homes on water, even homes in the trees. There are also studios, saunas, garden sheds, and greenhouses.

There are 1,300 photos, showing a rich variety of small homemade shelters, and there are stories (and thoughts and inspirations) of the owner-builders who are on the forefront of this new trend in downsizing and self-sufficiency. You can buy a ready-made tiny home, build your own, get a kit or pre-fab, or live in a bus, houseboat, or other movable shelter. Some cities have special ordinances for building "in-law" or "granny flats" in the back yard. There are innovative solutions in cities, such as the "capsules" in Tokyo.

If you're thinking of scaling back, you'll find plenty of inspiration shown by builders, designers, architects, dreamers, artists, road gypsies, and water dwellers who've achieved a measure of freedom and independence by taking shelter into their own hands.