Architecture is by no means a timeless medium - that much became increasingly clear during the course of the 20th century. The late 1960s in particular saw research done into techniques that would allow buildings to adapt to meet the demands made by time. Often this resulted in buildings that were programmatically neutral and characterless. The new challenge facing architects is to design for the unknown, for the unpredictable. ’Form follows function’ is giving way to concepts like polyvalence and semi-permanence. New spatial and physical structures generate freedom, taking time as their departure point. Alongside theoretical reflections, Time-based Architecture features projects that take account of the time factor, amongst which Rafael Moneo’s cathedral in Los Angeles, Gert Wingårdh’s apartment building in Malmö and Riken Yamamoto’s Shinonome Canal Court housing project in Tokyo.@en