Terreform, a nonprofit architecture collective transforms the rooftop of a building in downtown Brooklyn into a shelter and farm for urban refugees- people displaced by the mortgage crisis. Their two-week project, called Terrefarm, used only materials found in the building, and involved students and teachers from around the world. For more episodes in this series, visit: <a href="http://www.babelgum.com/newurbanism">New Urbanism</a>