Having a passion for urban transformation both Jeroen Koolhaas (HAAS) and Dre Urhahn (HAHN) were brought up in environments rich in architectural theory as both had relatives who were urban planners in Holland, where they are from. The duo works almost exclusively in underserved communities, where they mobilize local residents to transform their own neighborhoods through dynamic and colorful art projects on a massive scale. Working together since 2004, Haas & Hahn are perhaps most famous for their work in the favelas of Rio de Janeiro, Brazil which range from a single mural wall to whole streets covered in an explosion of color. Their activism in transforming communities through art has not gone unnoticed as they were recently asked to speak at the prestigious TED conference.