After rejecting the idea of reconstructing the factory after the war, Alberto and Piero Pirelli decided to create a management and administrative headquarters, leaving the manufacturing operations at the Bicocca plant. Two architecture firms, Valtolina-Dell’Orto and Ponti-Fornaroli-Rosselli, were entrusted in 1953 with drawing up the executive design, and overseeing the construction work and testing. The final building plans were completed in late 1954: it was to be a 127-metre, 31-storey reinforced concrete tower, with a ground plan that was wide in the middle, gradually tapering at the ends until it almost closed at the tips.
The architect Gio Ponti was assisted by the engineers Pier Luigi Nervi and Arturo Danusso, who were called in by Pirelli to design the reinforced concrete structure, and the definitive design was completed in 1956. The “Brusada” was demolished and the site prepared between June and December 1955, with the first stone being officially laid on 12 July 1956, in the presence of Alberto and Leopoldo Pirelli. The building was completed in 1960, and it was hailed by the international press as a technically and aesthetically exceptional work: the tallest reinforced concrete building in Europe and the third tallest in the world, it was a work of extraordinary and elegant rationality.
Solutions that had never been tested before in Italy were adopted for the construction site, and especially for vertical lifting: there were no conventional systems taller than 40 metres on the Italian market, so a system of two tower cranes was therefore designed to reach the height necessary for casting the roof slab over the top floor. The concrete production system, which was designed by the Comolli company, the contractor, also had unprecedented features.
The building was quite unique, both from an architectural point of view and in terms of its interior design.