SUMMACUMFEMMER is a practice based in Leipzig, founded in 2015 by Anne Femmer and Florian Summa. Their acclaimed cooperative project San Riemo (2020), a house for around one hundred inhabitants, is arguably one of the most important housing projects produced in recent years. San Riemo is a strikingly innovative scheme, featuring a field of neutral same-sized rooms, where kitchens replace corridors and the lines between apartment units are blurred. But beyond the architectural floor plan lies a world of challenges and a great deal of luck. In this interview with Jolanda Devalle, Summa and Femmer shed light on what goes on behind-the-scenes while designing and building experimental and affordable housing. From navigating fire safety regulations and other restrictive codes and standards, to decibels, radiators, and not-so-legal room partitions, the design of housing is for SUMMACUMFEMMER an open-ended exercise, for which there can be no “recipe.”