Raymond Lopez and Michel Holley's superlative scheme for the Caisse Centrale d’Allocations Familiales de la Région Parisienne (CCAFRP, shortened to CAF) was the talk of the town on its inauguration in 1959 . A “pioneering edifice”, hailed as “the first fully suspended curtain wall”, “unique in its plastic modelling”, and a testing ground in its own right, the ensemble has been fêted in our own time as a salient example of architectural production in the post-WWII era, not least on account of the constructional ingenuity applied to it and the assertive, not to say militant, urge to innovation that inspired it. (Fig. 1) But aside from the undeniable value it possesses in architectural and technical terms, the CAF, in Rue Viala, has another, still more recent claim to fame: its addition to the Inventaire supplémentaire des Monuments historiques (ISMH) in 1998 was annulled by a ruling of the Conseil d’État in 2002, after a long (and violent) legal controversy which pitted the heritage authorities – offshoots of the Ministry of Culture – against the Ministry of Social Affaires, the entity with custodianship of the CAF . Deprived of any protective measure under the Monuments Historiques, and long under threat of demolition, the CAF finally underwent a rénovation lourde – a programme of real estate development that, by the time it was completed in 2010, left part of it demolished, radically altered its physical character, and caused an irreversible loss of original material fabric.