I have seen this one before.  I like looking at the efficiency of the tiny houses.  The down side is finding a place that would allow them to be set-up.  

When you look at the "efficiency" of a space, one thing I found was that smaller trailers used the space so much more wisely than the larger slap them together types.  When it came to storage space, the bigger cheaper units did much less with cupboards and closets due to cost and you ended up with a LOT of floor space.