In the course of the 20th century it became increasingly clear that architecture is by no means a timeless medium. The late 1960s in particular were marked by research into techniques that would allow buildings to be adapted to suit the requirements of the day. 'Form follows function' is giving way to concepts like polyvalence and semi-permanence. New spatial and constructional structures generate freedom, taking time as their departure-point. Alongside theoretical reflections on such time-based architecture, this book illustrates countless projects involving the time factor, ranging from Shigeru Ban's Naked House, an apartment building in MalmÃÃÂ¶ by Gert WingÃÃÂ¥rdh to Kas Oosterhuis's Emotive House.