The Palace of Labour designed and built by Nervi and his son Antonio for the Turin exhibition of 1961 was the result of a competition held in 1959. The building-containing 85,000 square feet of exhibition space-had to be capable of conversion to a technical school at the end of the exhibition. It was erected in less than eighteen months.
Like Mies van der Rohe's buildings, there is a subtle fusion of structure and space in Nervi's buildings. But whereas Mies searched for free internal space, Nervi's aesthetic is dependent on an energetic exhibition of the structural parts of a building. The Palace of Labour was no exception... the simple 525 feet square shape was divided into sixteen structurally separate steel roofed compartments each supported on 65-foot-high concrete stems. The external walls, entirely clad in glass, wrapped round the perimeter of the building and incorporated large 70-foot-high vertical mullions.
Viewed as a symbol of integration between structural and architectural invention and presented in the most important national and international publications, the Palazzo del Lavoro has fascinated entire generations. This was achieved by emphasizing, with a certain mannerism, the overly exposed role of the structure, during the third phase of Nervi's career, that of the important international commissions when the "Nervi Style" became a repertoire of solutions to be used around the globe.
The competitive tender for the construction of the 47,000 m2 pavilion that, for the Centenary of Italian Unity, was to have hosted an important exhibition presided over by Giovanni Agnelli and designed by Gio Ponti, was issued in July 1959. In October of the same year the jury awarded the project to Nervi & Bartoli, and its designers: in addition to Nervi, his son Antonio and Gino Covre, one of the primary Italian engineers of steel structures. The project revolved around the subdivision of the square roof into sixteen independent 'umbrellas', each 40 meters per side, separated by continuous strip skylights and made from a sunburst pattern of steel beams fixed to a central column with a variable geometry, a recurring characteristic in Nervi's work after the Corso Francia Viaduct (1960), the Savona Railway Station (1961) and ending with the vault of the Cathedral in San Francisco (1970).
The perimeter gallery is instead constituted of Nervi's typical isostatic ribbed slabs, realized using moveable ferroconcrete formwork, based on a process widely tested by Nervi in various buildings, including the Gatti Wool Mill (1951-53). The proposal was deemed convincing for its simplicity and structural legibility and, thanks to the modular solution and differentiation in materials, it was the only submission capable of guaranteeing completion within the limited time available.
As with the Turin Exhibition, site supervision was managed by Fiat's Divisione costruzioni e impianti, directed by Bonade Bottino, with whom there existed a relationship of reciprocal trust. Beyond the technical data, nonetheless impressive - 158 meters per side, 26 meters in height, and a total volume of 650,000 m3 - the most innovative aspect was, in reality, the organization of the building site. Work began in February 1960 and by late December the building was already complete.
