Like a readymade for construction, the idea of prefabrication has long fascinated architects and designers. The kitchen and bathroom became special focuses for study because of the many different materials and trades required to produce them. Charlotte Perriand’s prefabs at Les Arcs—molded fiberglass shells in unexpected red, green, and blue—represent one of the rare projects of this kind that achieved large-scale production, with thousands of units created over the course of a decade. Completed at the end of Perriand’s career, these units were the culmination of many years of work to make domestic spaces more usable, affordable, responsive to contemporary life, and especially at Les Arcs, enjoyable and fun.