One Building, One City: World's tallest prefab, Sky City, is breaking ground in June : TreeHugger: This building puts 4,450 households on two acres and it is actually designed with energy conservation in mind. By going huge they are getting tremendous manufacturing efficiencies; by going vertical they get the kind of repetition that makes it affordable. By going half a mile high and 220 stories they are going to get noticed.
It is a vision of sustainability that people in a crowded world are going to have to get used to.