In 1952, Marcel Breuer, Bernard Zehrfuss and Pier Luigi Nervi, under the supervision of an international team of five architects (Lucio Costa, Walter Gropius, Le Corbusier, Ernesto Rogers and Sven Markelius) were commissioned to build the Unesco headquarters in Paris on Place de Fontenoy, opposite the military school and the Eiffel Tower.
As representatives of the Ciam (International Congress of Modern Architecture), their intention from the outset was not to miss the opportunity to make it a manifesto of the main principles of modern architecture, as was the case with the UN's Glass Palace.
The complex consists of three buildings on a site of 7,722 square metres. The 7-storey Y-shaped Secretariat is elevated on 72 pilotis 5 metres high, skilfully sculpted by Nervi, which earned him the nickname 'Michelangelo of reinforced concrete' given to him by the newspaper France Soir. The facades, on the other hand, are treated differently according to their orientation.
But it is especially in the Hall of General Assemblies and Commissions that Nervi's contribution emerges. Characterised by a single concrete shell forming the walls and roof that is folded accordion-like and therefore resistant in shape, the roof rests on a transverse beam supported by six pillars and on the side walls. The shafts of the pillars, following a geometry dear to Nervi, have a ribbed surface with a double curvature obtained by the transition from a circular section at the base to a rectangular one at the top. The third building, a four-storey cubic volume, also on pilotis, and echoing the same façade composition as the Secretariat, was added at a later date. The fourth building was never constructed.
Many recognise Unesco's unprecedented plastic and technical strength in which Nervi's role stands out, proclaiming here in a palace of international representation that concrete majesty he had always sought.
