When asked to build housing for 100 families in Chile ten years ago, Alejandro Aravena looked to an unusual inspiration: the wisdom of favelas and slums. Rather than building a large building with small units, he built flexible half-homes that each family could expand on. It was a complex problem, but with a simple solution — one that he arrived...

There's a creeping sameness in many of our newest urban buildings and streetscapes, says architect Vishaan Chakrabarti. And this physical homogeneity -- the result of regulations, mass production, safety issues and cost considerations, among other factors -- has blanketed our planet in a social and psychological homogeneity, too. In this visiona...