The Montréal Stock Exchange Tower is one of four skyscrapers constructed by Nervi: the Pirelli (1955-1958) in Milan with Gio Ponti, and, in Sydney with Harry Seidler, the MLC Centre (1971-1977) and Australia Square (1963-1965).
In the late 1950s, Montréal attracted many Canadian and foreign investors. Webb & Knapp was building the Place Ville-Marie (1957-1966) to a design by Ieoh Ming Pei, while the most important Italian construction company, the Società Generale Immobiliare, associated with the Banque Mercantile du Canada had commissioned Luigi Moretti and Nervi for the new Stock Exchange headquarters in Place Victoria.
The first project, released in August 1961, was one of the most ambitious: three 51-storey square towers set diagonally on top of a four-storey base above ground. The final project, revised for geological, regulatory and commercial reasons, and dated November 1962, ended up comprising only two twin towers of 48 storeys and 190 metres in height located on the initial part of the block and separated by a low building. Only one of the two towers will be built, but the construction will be very fast, just 351 days!
Nervi and Moretti, in very different ways, share the conviction that structure must be the basis of architecture. By exposing the framework in the façade, Nervi diversifies and hierarchizes the elements. The tower, enveloped in a light curtain wall of glass and aluminium, is dominated in expressive terms by the incisive presence of the pillars rising from the ground at each corner and by the complex geometry of its volume, at once pot-bellied and tapered. The load-bearing structure, consisting of a central core connected to the four corner pillars by three gigantic lattice girders on the fifth, nineteenth and thirty-second floors, is designed to make the framework less cumbersome and more resistant to the stresses caused by lateral wind pressure and earthquake tremors. This scheme was masterfully employed by Moretti, who exploited it to emphasise the tower's verticality, and to give the shaft an entirely classical rhythm, thus moving away from the prismatic skyscraper model.
