From the first months of his pontificate, which began on 30 June 1963, Paul VI had great confidence in the design of the new hall for the general audiences in the Vatican. It was he who directly called Nervi, who responded by drawing up an initial project as early as September 1963. The layout was defined at the beginning of 1964: a large volume with a trapezoidal plan covered by an undulating vault with a parabolic profile supported, on the entrance side, by ten white concrete pillars and, on the other side, by a hollow beam resting on two inclined pillars framing the papal throne. The hall, approximately 80 m wide and 100 m deep, with a maximum height of 18 m, is designed for a maximum capacity of ten thousand seats. The vault is realised with the system already adopted several times with prefabricated corrugated elements that serve as formwork for the casting of the ribs. Characteristic of the building is the white concrete with white marble grit.
Due to construction difficulties in the cramped spaces of the Vatican, the building site only started at the end of 1966 and was completed in 1971. In the years that saw the slow completion of the work, Nervi devoted himself to defining the ceilings and the glass eye, which only after a few variations reached its final oval shape, ribbed on the inside.
In keeping with Paul VI's intentions, the Vatican hall is not a church, but retains some of its fundamental requirements: the excellent visual and aural functionality, but also the 'severe, structurally comprehensible and distraction-free environment', the moderate lighting and the few easily intuitable images. Thanks to the planimetric configuration, the thickening and rising of the covering waves and the intensification of the lighting, the papal throne is the only visual and symbolic focus of an almost immeasurable space, which was only completed in 1977 by Pericle Fazzini's La resurrezione di Cristo group.
