Start a conversation on the subject of ‘flexibility’ with architects and you will inevitably find yourself caught up in a lexical field that is as rich as it is confusing. Is it really flexibility we are talking about? Or rather adaptability? Or perhaps versatility? In fact, isn’t it rather reversibility that is at stake? And what about modularity? And isn’t all this ultimately linked to prefabrication?

In reality, these different terms apply to different operations and maintain a hierarchy between them. They can concern multiple spatial scales and occur together or separately, at highly variable temporal rhythms. The book Flexible Housing, by Jeremy Till and Tatjana Schneider, is a valuable resource on the subject, providing some clarity on the possible definitions and permutations of ‘flexibility’ in the field of architecture, particularly in housing, where this concept has found fertile ground for its development.¹ The term is currently making a strong comeback, offering a salutary promise in the face of the rapid and untenable obsolescence of our built heritage. 1 Jeremy Till and Tatjana Schneider, Flexible Housing (Elsevier, 2007).