Zef Hemel (born in 1957) is a spatial planner. From 2012 to 2022, he occupied the Wibaut chair for Urban Affairs at the University of Amsterdam. Hemel studied Social Geography and Urban and Regional Planning at the University of Groningen. In addition to his academic work, he is employed by the Municipality of Amsterdam. Last year, Hemel’s newest book ‘Er was eens een stad’ (‘Once Upon a Time in Amsterdam’) was published in which he discusses the journey towards new spatial planning: visionary planning.