I'd never heard of this one - the Moonstone Project near Cheltenham. I was actually reading about Aquatron toilet systems (very clever little system) which referenced this. The house is insane, but well documented and some interesting elements - hours of video diary:
1500 sq m house, off grid water and sewage, walls U value of 0.06, heating on 6 days a year. Lots of concrete, but interesting anyway.