The Churches of San Gregorio Barbarigo and Santi Martiri dell’Uganda in Rome

This study aims to identify the figurative and symbolic meanings of Giuseppe Vaccaro’s plans for the churches of San Gregorio Barbarigo in the EUR neighbourhood (1970-1972) and of Santi Martiri dell’Uganda in the Poggio Ameno district (1975-1982), in Rome. These particular values may be recognized in the configuration of the layout, in the structural types and construction techniques used, and in how the two buildings’ materials were worked and put in place. These qualities must be preserved, because they define the current image of the works, and because they bear witness to the creativity of their architect. The reconstruction of the two churches’ creative and building process, and an understanding the compositional language used by Vaccaro (and the other professionals taking part in the work site) are an indispensable prerequisite for gaining knowledge of twentieth-century architecture and for defining effective operative strategies for protecting its spatiality, understood as the “place of image”.


Main text
The churches of San Gregorio Barbarigo in the EUR neighbourhood and of Santi Martiri dell'Uganda in the Poggio Ameno district in Rome, were built to the design of Giuseppe Vaccaro, respectively between 1970and 19721 and between 1975and 1982  The two buildings were designed and brought forward in the execution phases with the collaboration of Gualtiero Gualtieri, based on Sergio Musmeci's structural calculations of reinforced concrete, and under the direction of Ignazio Breccia Fratadocchi, on behalf of Pontificia Opera per la Preservazione della Fede e la Provvista di Nuove Chiese in Rome.
In its layout, the San Gregorio Barbarigo complex stands out for the church's cylindrical volume, accessed via two stairways converging in the portico raised from the level of Via Laurentina ( Figure. 1). Its surfaces are modulated by the vertical faceting of prefabricated concrete panels with a sharp edge to the outside and with straight-line partitioning inside. The distribution of the worship area, with a structure in reinforced concrete, is defined by four circumferences preceded by the longitudinal room with five entrances. This environment, with the hemicycle of confessionals to the left and the two stepped chapels to the right, underlines the axial form towards the presbytery and the assembly hall surrounding it. Arranged at the sides of the latter are the sacellum of the Holy Sacrament and the exedra with the Via Crucis ( Figures. 2,3).   The presbytery area, raised and lined with grooved slabs of white marble (with the mensa, ambone, the celebrant's seat, and the baptismal font), is covered by the framing of reticulated steel beams, with false ceiling. The structure pg. 179 is detached from the walls and is supported by metal pillars. The natural light filtering from the glass eye-hole and from the round skylight over the altar illuminates the liturgical scene and, with the narrow windows' stained glass, creates suggestive chromatic effects in the grooves of the exposed concrete panelling of the masonry surfaces ( Figure. 4). The meaning of Vaccaro's design work may be recognized in the reciprocal action of these spatial, symbolic, and psychological elements, which take concrete shape in the purity of the architectural lines, in the material nature of the open structure of the panels, and in the light they bask in. The different working methods for the exterior and interior wall facings identifies their intended use. In fact, the grooves are present on the walls providing the perimeter for the curved environments of greater liturgical importance (the area for worshippers and the presbytery, the exedras with the confessionals and the Via Crucis, the chapel of the Holy Sacrament), and are absent on the walls enclosing the other spaces, on which the lines of the concrete formwork may be seen (the church's pronaos and two chapels, the parish offices, and the rectory over the churchyard). In San Gregorio Barbarigo, this concept of architecture generates constructed shapes configuring the plan and structural types, but also establishes the construction technique and materials defining the church's style (Vaccaro, 1943, pp. 1,2).
The desire to establish a relationship with the existing context guided the choices in the first design solution for the Church of Santi Martiri dell'Uganda, proposed by Vaccaro in September 1970 3 . In fact, the "sense of place" and respect for the tall trees present in the area are the criteria underlying the architectural body's articulated design, which winds through the trees far enough from the trunks so as not to harm the roots. For this reason, the church was planned in the southeastern part of the available area, without plants, in correspondence with the intersection with Via di Grotta Perfetta. In the northwest portion, amid numerous trees, the sacristy, parish halls, and rectory rise in continuity ( Figures. 5,6).  The hall, with the churchyard in front surrounded by a high wall, is raised from road level and may be accessed via a staircase and a ramp converging on the entrance. The layout makes geometric reference to a triangle, and consists of curved exterior walls sandwiched by straight surfaces in correspondence with the vertices, onto which thin coloured panes open. Radiating from the three reinforced concrete pillars are the bands of the 72 ribs, linked by slabs, that support the exposed concrete roof and delimit a lower central space. This area, enclosed and lit only by the Plexiglas domes on the pillars, accommodates the liturgical foci (altar, pulpit, the celebrant's seat, and the baptismal font) and is distinguished by the side environments, taller and irradiated by the light penetrating from the detachment from the concrete exterior walls. In this way, the worshipers' attention is focused on the liturgical scene, despite the absence of a clear line of axis from the portal 4 . In the functional solution of the access from the street, in the articulation of the church building above the portico, in the vertical partition of the surfaces of the frontages, in the use of exposed concrete, but above all in the interaction between form, structure, and light and in the figurative and symbolic values derived therefrom, we can read some of the design solutions already tried out by Vaccaro in San Gregorio Barbarigo 5 .
The compositional criteria find only partial correspondence in the built church, after the modifications introduced by Ennio Canino.
The final project re-proposes the irregular conformation of the earlier plan, given the downward slope of the ground, but does not confirm the triangular geometric pattern, making reference, rather, to the design of a leaf. The layout on ground level is defined by curved perimeter surfaceswhose almost random arrangement is interrupted by straight walls broken by two accesses (lateral with respect to the altar, and covered by the overhang) and by the vertical windows to the left of the presbyteryand by the large pane of glass looking out onto the circular yard, onto which the adjacent building with the parish offices faces. However, the overall distribution is not effectively resolved, and the zones for the various uses cannot be clearly distinguished: the presbytery for liturgical activities, the chapel of the Holy Sacrament, the assembly room, and the confessionals. The building's bearing frame in reinforced concrete is formed by a large slab with recesses in expanded polystyrene, inclined like the roofs of Ugandan cabins, and is supported by five pillars of differing shape and section. The pillars are lined with sheet steel and rest on foundation piles with connecting beams and plinths. The slab varies in thickness: on a slope, from 78 to 18 cm towards outside the extrados, and irregularly stepped to the intrados, with 7 steps, 6 cm each (for a total of 42 cm), starting from the central slit with the skylight. Along the irregular perimeter, the curb at the edge links the structural elements and balances the roof's overhang beyond the exterior walls, from which it is separated by the continuous horizontal pg. 181 window 6 . This solution brings to mind Vaccaro's earlier one, but in this case the light that penetrates from the glass eye-hole blends with that originating from the over openings, from the window overlooking the yard, and from the long skylight, but is dampened by the presence of the trees. Therefore, no effective games of colour, light, and shadows are created on the walls' vertical strips in relief, or on the grooves of the low ceiling, but the large environment remains in penumbra ( Figures. 7,8,9).   It is an unresolved, unharmonious place, due also to the use of highly dissimilar materials: marble for the surface work of the interior and exterior walls, exposed concrete for the ceiling, steel for the lining of the pillars, more or less stained glass for the windows, two-toned earthenware for the floor, and travertine for the liturgical furniture ( Figure.  In the final analysis, the church of Santi Martiri dell'Uganda, although built with bold structural solutions particularly for the roof, does not achieve the emotional tension and the mystical breadth of the church of San Gregorio Barbarigo. These effects, in this case, are obtained via the plan's controlled geometry, the correctness of the distribution system for the environments and the related functions, the purity of the architectural language and the upward expansion of the hall, the wise use of materials and how they are worked, and the shrewd use of light.
The study of the Roman churches of San Gregorio Barbarigo and Santi Martiri dell'Uganda spurs some reflections on the process of conceiving and carrying out the architectural work, and on the need to define intervention strategies to protect its symbolic and figurative values.
At the time of Giuseppe Vaccaro's death in September 1970, the foundations of San Gregorio Barbarigo had been completed, and the site was run by Gualtiero Gualtieri, who drew up the execution documents. While this circumstance ensured the works' completion on the basis of the original designs, it did not prevent the occurrence of shortcomings in the management of the works and in the relationship with the contractor maintained by the works manager Ignazio Breccia Fratadocchi. All this resulted in clear phenomena of decay shortly after the closure of the construction, with consequent urgent interventions on the roofs and exposed concrete surfaces between 1987 and 1990. The lack of continuity between the moment of design, the implementation phase, and the control operations during the works, due to the various professional figures who took part, significantly impaired the preservation of the exposed facings of the church, in whose mode of construction Vaccaro's poetics are to be read.
In Santi Martiri dell'Uganda, the question is posed in different terms. Ennio Canino succeeded as designer when the building of the parish halls had already been completed, and the general criteria for building the hall had already been established by Vaccaro and Gualtieri, in relation to the existing setting 7 . History teaches that in a building's execution process, it is unusual for there to be a succession of a number of professionals, even when the works have already begun, given that architecture, by its very nature, changes as people's life needs vary even over the short term. However, in the church of Santi Martiri dell'Uganda, although re-elaborating Vaccaro's original idea was perfectly allowable, Canino appears to have designed without comprehending the study of Vaccaro's spatiality and the meaning of his figurative lexicon. In fact, the current arrangement lacks the coherence of Vaccaro's geometrically, structurally, and constructively correct compositional mastery, and his continuous search for harmony amid spaces differing with respect to their functions. 7 The graphics for the parish works, the rectory, and the residences, drawn up by Giuseppe Vaccaro and Gualtiero Gualtieri, but signed only by the latter, were approved by Ripartizione XV Urb. Edil

Conclusion
To conclude, the reconstruction of the design path of the church of San Gregorio Barbarigo and that of Santi Martiri dell'Uganda shows the need for in-depth knowledge of the formal language of twentieth-century architecture, with its specific historical and artistic values. Understanding the compositional choices and the poetics of the various architects, and analysis of the history of the building, of the work site's management, of technologies, and of the working of the materials, are now prerequisites for setting out effective intervention strategies to deal with the multiple problems in preserving buildings from the second half of the twentieth century, as "places of image".