The creation of something this sustainable (especially for lower and middle income communities) needs an equally sustainable tool-shed and parts factory for use at the same time.

These are not things that industry tends to provide on an individual or even communal basis, so they will most likely have to be built into communities themselves through fabrications labs and community-owned 3d printers.

neil gershenfeld's talk on fab labs and their social applications if anyone's interested (warning: tedtalk)

https://www.youtube.com/watch?v=5n-APFrlXDs

he has a bunch of good ideas. if anyone's curious, buy his books or watch any of his most recent talks discussing digital reality