Take a walk on the moon at SANAA’s Lausanne Rolex Learning Center, a whimsical interior landscape embedded with a spirit of collaboration. In Shenzhen, Steven Holl put a skyscraper on its side, then lifted it into the air. Meanwhile, retired doctor Raymond Neutra has been making a habit of spontaneously dropping in on people living in houses designed by his father, Richard. Koen van Velsen’s rehabilitation centre in Arnhem, the Netherlands, offers a healthy dose of functionality. We go one-on-one with South African Leon van Schaik, who talks about apartheid, ethics and the translation of architecture from one situation to another.