There are also various initiatives and competitions in the "sustainable living" space that fit the bill, such as https://www.solardecathlon.gov
In my notebook I sketched out a possible windmill / pump idea that would pump water to a reservoir which, when full would 'flush' for all of the commodes it served. Challenges are odors and blockages, and a reliable sluice system.
And what would it be like if you let people cook with fire in their space? (lots of small spaces in Brazil and India with simple three stone type cookfires. Is it possible to accommodate something like that without creating an undue fire risk?
[1] http://www.mercurynews.com/2017/08/28/san-jose-proposes-just...
They are high-efficiency, low-smoke wood stoves and the company actually tries to make a difference to people that rely on fire for cooking: https://www.bioliteenergy.com/pages/mission
I've had the camp stove for a couple of years and it works really well. I wouldn't recommend using it indoors (the monoxide risk if nothing else), but it definitely fits in with the off-grid movement.