[nobodysfool]

This doesn't have a bathroom, it's just a place to sleep and work. Think of it like a workroom, or greenhouse. It was built on a foundation of masonry blocks and 2x4s If you wanted plumbing, you could certainly add it. That's the idea, you build it yourself.

[dsuth]

I wonder at what point the structure would become non self-supporting though, in terms of scaling up the size.

[smoyer]

I'd actually try going green in one of these - a composting toilet (http://www.letsgogreen.com/index.html) and plumbing that collects rainwater, then drains into a gray-water tank to be used on the gardens.