The last part of the complete work, volume 4 is largely devoted to the ARCS, a Savoyard winter and e t leisure resort. For plus twenty years, Charlotte Perriand, a pioneer in bioclimatic architecture, led the urban and architectural design of Arc 1600 and Arc 1800, in collaboration with a team of architects. She also designed the interior architecture of plus 4,500 homes, intervening right down to the choice of the little spoon.