The building is remarkable for its bulk, the deep-set arch over the entrance and the series of statues (added at a later date) placed on the columns and pilasters that punctuate the facade.
The monumental effect is concentrated chiefly on the central portion of the facade, while the setback of the upper floor and the compact volumes that define the front of the building, as well as the interior spaces, all still seem to derive their inspiration from Purism. Compared with the other designs submitted for the competition, Piacentini’s is surely the least eclectic, one in which the classicist tradition (the triumphal arch entrance, the pilasters breaking the flat surfaces of the outer walls, and the central plan and symmetry of the interior) is mitigated to an extent by the search for an international style.
The problem of style was the heart of the architectural debate of the period, and the competition to design the Palazzo delle Esposizioni was marked by repeated clashes over the question. "A building with no windows" – this was one of the most controversial elements of the design, along with the "French" influence at the cost of adhesion to a national style, which caused conflict within the adjudicating commission itself, but, more importantly, gave rise to a highly critical campaign on the part of the press.
For the most part, the search for a national style coincided with a revival of historical styles, which meant that classicism was no longer the exclusive standard to dominate. In the process of transforming the urban fabric of Rome, however – from roads, to representative buildings, to residential construction – what prevailed were notions that had little to do with the city’s tradition. The laying out of new streets, which included large-scale demolition wherever possible; the opening of wide boulevards and arrow-straight avenues, and the construction of bulky government buildings and apartment blocks that echoed their design, albeit more modestly, were an obvious reference to the metamorphosis of Paris under Napoleon III (as well as the tradition in Italy’s Piemonte). The pre-eminence of the city’s historic structure, however, could only foil a broad scheme of this kind and jeopardize that balance between ancient and modern understood by Pianciani to be the vocation of Rome, the capital of a united Italy.
In actual fact the critics of the design for the exhibition hall failed to understand its most significant features. The lack of windows was intended to create continuous interior surfaces that would exploit exhibition requirements to the utmost, while the transparency of the ceilings in iron and glass would allow natural light to enter from above, which was considered the light most suited to the building’s functions. Finally, the symmetry of the layout – the convergence of the six large rooms around the central rotunda, the mirror-like nature of the two parts of the building which allows for continuity in the design and a linear route through the rooms both horizontally as well as vertically – all served to define an open space, but one convergent on a centre, and one in which the loftiness of the design is visible mainly in the decorative elements (the stuccoes, the coffered ceilings, the marmoridea that covers part of the colonnade).
Costantino Dardi, the architect who restored the building a century later, salvaging as much of the original design as possible, had this to say about the building’s interior, calling it a space "in which the theme of visibility dominates: looking, and looking sidelong, appear to be the constant in the design’s aim. Looking from the street to the inside and from inside to the street; looking down from above and up from below; looking at the rooms from the grand staircase and at the staircase from the rooms; stretching one’s glance over the long view and then padding it with canvases, frames, panels and screens that in some spots throw the building’s luminosity into shadow."
The back of the building was originally covered by a ceiling in glass and iron (which will be reproduced in a modern version in the course of the current restyling); this was a transparent space that the architects intended as a link between the interior and the gardens outside that faced the Palazzo del Quirinale. Indeed, the question of how to link interiors to the outside was one of Piacentini’s overriding concerns: how to transcend the narrow confines of the site allotted to the exhibition hall, which seriously cramped the design’s style and made its monumental air incongruous. Piacentini first considered dismantling the church of San Vitale piece by piece and reassembling it inside a park, thus creating an ample space around the building; later he thought of realigning the church’s axis around that of the street and raising the church to the same street level as the exhibition hall. Finally, all too aware of the church’s isolation, only heightened by the lowering of the street level in order to create the tunnel under the Quirinale, he designed a staircase with two ramps that would embrace the base of the church itself, a solution that was almost Baroque. These plans were not approved, however, and the architect only added on to the outer staircase by building two new levels.
The statues were added to the facade in the late 1980s, although they do happen to reflect the decorative scheme of the original architect himself. The sculptors were from the academic school (Cencetti, Biggi, Aureli, Trabacchi, Ferrari, Galletti and others), and the subjects were equally academic: at the top, art sustained by peace and knowledge; on the portico’s four pillars architecture, sculpture, painting and industrial art; along the balustrades twelve artists from the past.
The exhibition hall was inaugurated on 21 January 1883 in great pomp, in the presence of the King of Italy. Initially the exhibition itself was to be limited to Italian artists alone, but was then opened to a few foreign artists, a limited number of minor importance. There was a clear political significance to the exhibition, which reflected a cultural milieu that was academic and traditionalist to the extreme. For the most part, the subjects of the works were drawn from episodes in Roman history whose symbolism was enhanced by the recent battles of the Risorgimento, or else by themes inspired by the early days of Christianity. There was a studied equilibrium, therefore, between secular and religious elements. Not to mention the landscape paintings, which were a testament to an academic style far from the exploration of realism that the advent of impressionism was consolidating in France and other European countries, even influencing the selection process at the official salons.