Head of the Institute for the History and Theory of Architecture at ETH Zurich, Professor Philip Ursprung gives the inaugural lecture of the new academic year at the Vallès School of Architecture, ETSAV (UPC).

He analyses the concept of terrain vague, coined by Ignasi de Solà-Morales thirty years ago, and its relationship with public space. In the 1990s, these sites—for example, industrial wastelands and monotonous suburban developments often ignored in mainstream architectural discourse—indefinite spaces but open to transformation, were seen as an opportunity to rethink the city and collective spaces. Philip Ursprung revisits the idea, tracing its evolution over time and exploring the new possibilities it offers for imagining the future of public space.

Emphasising the inspiration that many participative initiatives represent today, he champions the revival of shared public spaces and the relevance of terrain vague as a valuable tool for creating new urban imaginaries.