The Brick Romanesque: Volumetric Symmetries and Vaulting Mechanics in the Abbey of San Nazaro della Costa

Perched on the modest elevation the Novaresi have long called the colle della Vittoria — its brick mass visible against the flat geometry of the Po plain — the Abbey of San Nazaro della Costa encodes in mortar and fired clay a thousand years of architectural intention. What the building presents to the historian of construction is not a pristine specimen of any single moment but a working palimpsest: Romanesque spatial logic underneath, Gothic structural ambition layered above, Renaissance light cut through walls whose thickness still whispers of an older structural system. To read San Nazaro della Costa is to read the Lombard brick tradition from the inside out.

Tenth-century foundation, millennial continuity: The site sustained a church dedicated to the martyr Nazarius from before 1000 CE; the first surviving documentary attestation dates to 1124, with a second cluster of records from 1155 to 1157 confirming the church stood outside Novara’s city walls on a slight natural rise whose topographic nickname — la costa, the slope — gave the complex its enduring name.
Three building campaigns define the current fabric: The Poor Clares rebuilt the church between 1256 and 1265 as a three-nave basilica; Franciscan Observants oversaw a radical structural transformation between 1470 and 1500 — demolishing the original nave pillars and raising large pointed arches — while Renaissance patrons subsequently opened wide windows and added the portico towards the cloister.
The Lombard brick grammar underlies every phase: Fired brick (the mattone of the Po Valley, product of the region’s alluvial clay deposits) remained the constructive medium across all periods. Pilaster strips, corbel tables, thick load-bearing walls, and the management of vault thrust through sheer mass are Romanesque principles that the building’s later Gothic and Renaissance interventions either accommodated or directly exploited.
Vaulting mechanics trace an arc from Romanesque mass to Gothic line: The structural trajectory of the building moves from the deep-wall barrel and groin vaults typical of early Lombard construction through to the pointed transverse arches of the late fifteenth century — each system carrying distinct thrust characteristics, each demanding different abutment strategies from the surrounding brick mass.
An exceptional fresco environment overlays the structural stratigraphy: The pictorial program runs from a thirteenth-century Deposition of Christ through 1330-1340 works attributable to the Giottesque school and a 1346 cycle by Giovanni da Milano, to Giovanni Antonio Merli’s Sant’Antonio of 1474 and the late fifteenth-century Crucifixion in the apse — a painted record of artistic exchange between Novara and the broader Lombard cultural world, applied directly to the plaster-skinned brick surfaces the structural campaigns produced.

Introduction: The Abbey, the City, and the Brick Horizon

Novara sits near the western boundary of the Lombard plain, geographically within Piedmont but architecturally within the orbit of the great building tradition that the Po Valley’s alluvial floor made possible: the architettura lombarda, which shaped ecclesiastical and civic space from the Alpine foothills to the Adriatic with a consistency of material and method unmatched in medieval Europe. The abbey of San Nazaro della Costa belongs to this tradition in the most fundamental sense — not because its current fabric presents Romanesque stonework in any preserved or pristine form, but because the building’s entire structural logic, from the thickness of its walls to the spatial proportions of its nave and aisles, was inscribed in the tenth and eleventh centuries in the language of Lombard brick construction and has never been entirely overwritten.

The topography of the site is itself meaningful. The colle della Vittoria — a modest but perceptible rise above the flat surrounding plain, sufficient to give the complex visibility from the city while maintaining its extra-urban character — was chosen precisely because it placed the church in the liminal zone between the civic and the sacred that medieval urban thinking required. The church stood fuori le mura, outside the walls, but within sight of them: a position that in the organization of medieval Novara carried associations of martyrdom, pilgrimage, and the threshold between the world of the living and the world of the dead that the proximity of the cemetery would later reinforce. The costa, the slope, gave the complex both its name and its position in the city’s sacred topography.

The building’s history is one of continuous remaking rather than singular construction. Its tenth-century origins — a church dedicated to the martyr Nazarius, attested before any surviving document and confirmed by the cluster of records from 1124 and 1155 to 1157 — represent the Romanesque foundation layer from which all subsequent development proceeds. The Poor Clares who inhabited and rebuilt the complex between 1256 and 1265 produced the three-nave basilican structure whose spatial logic the building still follows. The Franciscan Observants who received the complex in 1444, energized by the reforming spirit associated with San Bernardino da Siena, presided over the most dramatic structural transformation — the 1470 to 1500 campaign that demolished the original nave pillars and raised the large pointed arches that now define the interior. Renaissance patrons added light and portico in the decades that followed.

To analyze San Nazaro della Costa architecturally is therefore to engage with a problem common to much of the Po Valley’s built heritage: the building as palimpsest, each layer partially obscuring and partially revealing what came before. The Romanesque stratum is not visible in isolated survivals the way a single Lombard campanile or a quadriportico fragment might be at other Novarese sites. Instead, it survives as a set of structural and spatial constraints that each subsequent campaign had to negotiate — the wall mass, the plan geometry, the bearing capacity of the foundations — and in negotiating them, perpetuated the Romanesque logic even while transforming its surface expression.

The Lombard Brick Tradition: Maestri, Material, and Constructive Method

The architettura lombarda is a designation that has accumulated scholarly weight since the nineteenth century — when Raffaele Cattaneo first systematized its characteristics — and that names a building tradition whose geographical reach far exceeded the political boundaries of Lombardy. From the early eleventh century, the craftsmen the medieval world called magistri comacini — master builders from the lakes region around Como who possessed proprietary knowledge of Lombard brick construction techniques — carried their skills across Europe. The Lombard bands, the corbel tables, the pilaster-strip articulation of wall surfaces that appear in the Pyrenees and the Rhineland as well as across the Po plain testify to the extraordinary diffusion of a technique rooted in the specific material conditions of northern Italy.

Those conditions were, above all, geological. The Po Valley’s alluvial deposits are clay-rich in a way that makes fired brick the natural building material — not a substitute for unavailable stone but the preferred medium of a tradition with deep Roman antecedents. The Roman urban infrastructure of Mediolanum, Ticinum, Novaria, Cremona, and Laus Pompeia had been built in brick; the medieval builders who inherited their sites also inherited the brick-making knowledge and the brick-field locations that made the material abundantly available at modest cost. When the bishops and abbots of the eleventh and twelfth centuries commissioned new churches, brick was not a compromise: it was the local expression of structural intelligence.

The Lombard structural vocabulary that developed within this material context is both immediately recognizable and internally coherent. Lesene — flat pilaster strips, one brick width in projection, bonded into the wall fabric at regular intervals — articulate the exterior wall surface while serving a structural function: they increase the effective thickness of the wall at the points where transverse arches, if any, bear down on the outer face, and they provide a visual register of the bay system organized on the interior. Archetti pensili — corbel tables of small hanging arches that run along the eaves, supported on corbels projecting from the wall face — define the roofline and participate in a larger compositional system of horizontal stratification that gives Lombard Romanesque churches their characteristic rhythm of registers: blind arcade at the base, pilaster strip articulation in the middle zone, corbel table at the summit.

The structural ambition of the Lombard builders was the vaulted nave — a problem that occupied architects across Europe from the tenth century onwards and that demanded creative responses to the challenge of lateral thrust. In the Lombard tradition, the preferred early solution was the massive wall: walls thick enough, at the springing of the vault, to absorb horizontal thrust without deflection. This solution traded elegance for reliability. The thick-wall basilica with barrel-vaulted nave and groin-vaulted aisles — a type exemplified at Sant’Ambrogio in Milan, San Michele in Pavia, San Zeno in Verona — generated a spatial experience of great power: the nave compressed laterally by walls of substance, the vault pressing down with physical authority, the darkness of the interior relieved only by small clerestory windows cut cautiously through the structural wall mass.

Within this broad tradition, the Novarese and Vercellese subregion developed its own characteristics. The proximity of the Sesia river and its tributary systems — the same waterways that brought stone from the Alpine foothills when stone was used for dressings, moldings, and capitals — shaped the material economy of local construction. In Novara, the dominant material remained brick throughout the Romanesque period, but brick of high quality: the cotto decorative work that appears in capitals, portal moldings, and corbel tables at Novarese sites shows the local brick-working tradition operating at the level of precision craft as well as structural utility. The Novarese Romanesque is embedded in, but not reducible to, the broader Lombard category.

Paolo Verzone’s foundational studies of Vercellese Romanesque architecture, and the subsequent scholarly tradition from Antonio Aina and Giovanni Donna d’Oldenico, have established that this subregion possessed a coherent architectural culture with its own proportional preferences and ornamental conventions. The buildings around Novara and Vercelli — the fortified abbeys of San Nazzaro Sesia, the collegiate churches of Vercelli, the Baptistery of Novara, the scattered rural pievanie of the Piedmontese plain — form a recognizable family within the Lombard tradition, and San Nazaro della Costa is a member of that family even in the fragmentary and modified form in which it survives.

Site, Foundation, and the Genesis of the Three-Nave Plan

The etymology of the site name — della costa, of the slope — establishes the building’s topographic situation with precision. The colle della Vittoria on which the complex stands is not a commanding height but a sufficient one: enough elevation to lift the church’s mass above the surrounding urban fabric, to give the campanile visual leverage over a broad sector of the plain, and to position the religious community in the interstitial zone that medieval urban theology recognized as appropriate for extra-mural monasticism. The church stood fuori le mura from its earliest attestation — a positioning that associated it with the martyrial tradition of saints buried outside city walls, and that maintained a practical distance from the density and disorder of intra-mural urban space.

The first historical record of a church at San Nazzaro de coste comes from 1124, a document whose existence confirms that the building was already established and sufficiently significant to merit administrative mention. A second group of records from 1155 to 1157 elaborates the picture: the church dedicated to the martyrs Nazarius and Celsus existed as an active religious site before the documents that describe it, and the scholarly consensus places its origins in the tenth century — contemporary with the wave of church founding and rebuilding that followed the consolidation of Lombard episcopal authority across the Po Valley and the stabilization of communities disrupted by Magyar incursions in the ninth and tenth centuries.

The tenth-century structure was almost certainly a simple aisleless hall or a modest single-nave basilica — the typical form of a rural or suburban oratorio at this date — built in brick, roofed with timber or a low barrel vault, and oriented in the standard liturgical east-west direction. Its position outside the city walls gave it the character of a martyrial chapel serving pilgrims and the population of the extra-mural quarter. That this building had no independent monastic community attached to it for its first two centuries is suggested by the absence of any reference to regular canons or monks in the surviving documentation until the Poor Clares arrive in 1256.

The installation of the Poor Clares of San Pietro di Cavaglio between 1256 and 1265 was the transformative event for the building’s architectural history. The Clarissan community required a conventual church of sufficient scale to accommodate their liturgical life — choir stalls, processional space, visual access to the altar — and the existing simple structure was inadequate. The rebuilding they undertook produced the three-nave basilica whose spatial geometry the building has maintained through all subsequent campaigns. The specific detail that the rebuilt church was organized in three naves is architecturally significant: it marks the adoption of the basilican type associated with Lombard Romanesque ecclesiastical prestige rather than the single-nave hall characteristic of mendicant buildings in their most austere phase.

The three-nave plan implies a specific constructive commitment: nave arcades supported on columns or pillars (the pilastri delle navate that the 1470-1500 campaign would later demolish), flanking aisles lower than the central nave, and the structural challenge of lighting and vaulting the central nave space in a manner compatible with the structural capacities of the existing perimeter walls. The 1256-1265 campaign almost certainly retained the earlier perimeter wall positions, rebuilding the interior structural system while conserving the exterior shell that defined the building’s site footprint and that was already bonded to the ground in ways that made wholesale relocation impractical.

Vaulting Mechanics in the Lombard Brick Tradition

The structural problem that defines Lombard Romanesque architecture at its most technically ambitious is the vaulting of a wide nave in brick — a material whose compressive strength is adequate for arch and vault forms but whose tensile resistance is negligible, making the management of lateral thrust the central engineering challenge. Understanding how Lombard builders approached this problem illuminates not only the specific vaulting systems at San Nazaro della Costa but the structural logic that shaped the entire family of Po Valley ecclesiastical buildings to which it belongs.

A barrel vault is the simplest continuous vault form: a semi-cylindrical surface generated by extruding a semicircular arch along the longitudinal axis of the nave. Its structural behavior is that of an extended arch: the vault’s curved geometry converts vertical load — the weight of the vault itself plus any material above it — into oblique compression directed along the vault surface. At the springing points, where the barrel vault meets its supports, this oblique compression resolves into a vertical component (downward, absorbed by the wall or pier) and a horizontal component (outward, constituting the lateral thrust). The horizontal thrust is the structural problem: it requires that the support at the vault’s base be either massive enough to absorb it without deflecting, connected to a counter-thrust of equal magnitude, or braced by an external buttress.

Early Lombard builders chose the mass solution. The perimeter walls of a barrel-vaulted nave in the Lombard tradition — Sant’Ambrogio’s nave walls, for instance, or those at the Benedictine abbeys of the Milanese countryside — are thick enough to function as structural counterforts: self-sufficient abutment masses capable of absorbing vault thrust through the inertia of their own weight. This approach places constraints on window openings, since every opening in the wall is a local reduction of the mass available to resist thrust, and it produces the characteristic visual character of the Lombard Romanesque interior: weighty, dimly lit, architecturally severe.

The groin vault — formed by the intersection of two barrel vaults at right angles — represented a structural refinement. Where a barrel vault generates continuous lateral thrust along its full length, a groin vault concentrates thrust at the four corners of the bay: the diagonal groins (the lines of intersection between the two barrel surfaces) carry the vault’s load to specific points, allowing the intermediate wall sections between corners to be thinned or opened. This concentration of force at defined points made it possible, in principle, to support the vault on isolated piers rather than on continuous wall masses. The aisles of major Lombard Romanesque churches — vaulted with groin vaults while the nave received the barrel — demonstrate this structural logic: aisle vaults are lighter, their thrust manageable at the outer wall, while their inner edge presses against the nave wall precisely at the base of the nave vault’s springing, providing lateral restraint by counter-thrust.

The ribbed vault — the decisive innovation that carried European architecture from Romanesque to Gothic — achieved a further concentration of structural work. By running stone or brick ribs along the diagonal groins and the transverse and longitudinal edges of the vault bay, the ribbed vault created a skeleton of active compression members (the ribs) supporting passive infill panels (the webs or severies) that carried only their own weight. The ribs were thickened and shaped to carry load efficiently; the webs were thinned to reduce weight. This structural separation reduced the total weight of the vault and, consequently, the thrust it generated — which is why Gothic pointed arches were structurally advantageous even beyond their increased height: a pointed arch of a given span generates less lateral thrust than a semicircular arch of the same span, making Gothic vaulting both lighter and less demanding of its abutments.

At San Nazaro della Costa, the trajectory from Romanesque mass to Gothic line can be traced through the two major structural campaigns. The Poor Clares’ 1256-1265 rebuilding almost certainly employed cross-vaulting — simple ribbed or groined vaults over the bays defined by the new nave arcade — of a type consistent with the mid-thirteenth century Lombard construction practice that was absorbing Cistercian and early Gothic influences from northern France. The bays were defined by the pilastri delle navate — the nave pillars that organized the arcade — which carried not only the arcade arches but the vault ribs descending to the pier capitals. The entire system of pillars, arcade arches, and vault ribs formed a structural skeleton embedded within the thick perimeter walls that the campaign inherited from the earlier building.

The 1470-1500 transformation fundamentally altered this structural logic. The demolition of the pilastri delle navate — the removal of the intermediate vertical supports that had organized the entire structural skeleton — was an act of considerable structural boldness. In place of the arcade system, the builders raised large pointed arches (grandi archi a sesto acuto) that spanned the full width of what had been the nave and aisle combination. These arches, springing from the perimeter walls rather than from intermediate piers, concentrated their thrust directly on the existing wall mass. The thick walls that were a legacy of the Romanesque structural philosophy provided the abutment that the new Gothic arches required — a case in which the earlier structural decision (build walls thick enough to absorb barrel vault thrust) inadvertently provided the correct structural solution for a quite different later system.

The Wall as Structural Surface and Expressive Plane

In the Lombard brick tradition, the wall is not merely the boundary between interior and exterior space: it is the primary structural element, the carrier of both the building’s loads and its expressive program. Understanding the wall system at San Nazaro della Costa — in its Romanesque origins and through its later modifications — requires attending to the wall both as engineering object and as architectural surface.

The structural wall of a Lombard Romanesque church operates in compression through its full thickness, not merely at its surface layers. The brick bonding of Lombard construction — characterized by the alternation of stretcher and header courses in patterns that tie the inner and outer faces of a thick wall into a unified monolithic mass — produced walls that behaved as solid bodies of compressive material rather than as thin shells. This monolithic behavior was critical for resisting vault thrust: a wall that delaminated under lateral force (separating into inner and outer faces that buckled independently) would fail catastrophically, while a well-bonded monolithic wall deflected slowly under sustained thrust, providing warning before failure.

The articulation of this wall surface through lesene (pilaster strips) and archetti pensili (corbel tables) served structural purposes beyond their visual role. Lesene, bonded into the wall at intervals corresponding to the interior bay system, locally increased the wall thickness at the points where transverse arch loads were delivered to the perimeter — precisely the points of maximum thrust concentration. The additional mass at these locations provided additional resistance without thickening the entire wall, a geometrically efficient approach to variable load distribution. The pilaster strip is therefore both a decorative motif — the external articulation of the internal bay rhythm — and a structural response to the uneven distribution of vault forces along the wall.

Corbel tables — the archetti pensili that run along the Lombard eaves — served a different but complementary function. By projecting the eaves line outward on a series of corbels and small arches, the corbel table created a deep shadow at the wall’s upper boundary that visually defined the wall top while directing rainwater away from the wall face. Structurally, the corbel table’s slight cantilever over the wall face added weight at the wall’s outer edge — a modest but real contribution to the overturning resistance of a wall under lateral thrust. The corbel table also served as a visual terminus for the pilaster strip articulation below: each lesena terminated at or adjacent to a corbel supporting one of the small arches of the corbel table, completing the vertical connection from foundation to eave in a continuous articulated element.

The facade of a Lombard Romanesque church represented a particular challenge in this wall logic: the west facade was the building’s public face, required to carry the roof loads of the nave at its apex while presenting an architecturally legible surface to the urban or conventional space before it. The facciata a capanna — the gable facade whose profile followed the pitched nave roof — was the preferred Lombard solution: it read honestly the section of the building behind it, registering the stepped heights of nave and aisles in a continuous masonry surface that was large enough for a significant sculptural or decorative program but sufficiently disciplined to maintain the wall’s structural integrity. At San Nazaro della Costa, the Renaissance intervention of enlarged windows in the facade surface modified this structural balance — the large openings cut into what had been a relatively solid wall mass introduced local weaknesses that the overall structure was thick enough to absorb, but that changed the visual and structural character of the wall from Romanesque solid to Renaissance permeable.

The Campanile: Vertical Accent and Structural Autonomy

The campanile is among the most distinctive contributions of the Lombard architectural tradition to the European building repertoire. The free-standing or engaged bell tower — distinct from the building’s main mass, rising to heights that gave it dominance over the surrounding landscape — was a Lombard invention of the ninth and tenth centuries that spread across Europe as the Lombard building tradition spread. Its structural logic is that of a vertical column of brick: a square or circular section of massively bonded masonry that gains stability from its own weight and from the quality of its base bonding to a broad footing on stable ground.

The typical Lombard campanile ascends in horizontal registers differentiated by their window openings. The lower registers, solid except for narrow slits, carry the greatest lateral loads (wind pressure on a tall tower diminishes with distance from the ground only at higher sections) and require the greatest wall thickness. As the tower ascends, windows widen progressively — from single-light openings in the lower registers to bifora (two-light windows divided by a central column) in the middle section to trifora and ultimately multi-light openings in the belfry stage. This progression serves both functional and optical purposes: the belfry windows must be wide enough to project sound outward effectively, while the progressive opening of the wall surface from solid to permeable counters the visual impression that a uniformly solid tower would create of taper and diminution as height increases.

The optical refinement of Lombard campanili reflects a sophisticated understanding of how vertical masses read at distance. A tower whose walls are uniformly thick, uniformly textured, and uniformly coloured reads as monolithic — powerful at the base, still powerful at the summit, with no visual mechanism to articulate the distance between them. The horizontal banding that the Lombard builders introduced — through corbel tables at each register boundary, through string courses of projecting brick, through the change in wall texture that window openings produce — creates a measured vertical rhythm that the eye climbs rather than merely scanning. The spectator perceives not a uniform column but an articulated sequence of registers, each with its own proportional character, that composes into a coherent whole.

The campanile at San Nazaro della Costa participated in this tradition of vertical Lombard composition within the specific urban context of Novara — a city whose campanile landscape was shaped by the Duomo, the Baptistery, and the collegiate and conventual churches of the intra-mural fabric. The extra-mural position of San Nazaro meant that its campanile had a different role from a purely urban tower: it served as a landmark visible from the plain, a locating element for travelers approaching Novara from the west and from the Sesia river valley, and a vertical punctuation of the otherwise horizontal silhouette that the flat Po plain creates on the horizon.

The Romanesque Foundation and Its Gothic Transformation

The 1470-1500 campaign at San Nazaro della Costa was not a destruction of the Romanesque but a Gothic reorganization of a space whose Romanesque bones had already been substantially modified by the 1256-1265 rebuilding. Understanding the nature of the transformation requires reconstructing, from the surviving evidence, what the successive states of the building would have looked like and what structural choices the 1470-1500 builders faced.

The Poor Clares’ rebuilding of 1256-1265 produced a three-nave basilica in a constructive idiom informed by both the Lombard Romanesque tradition and the Cistercian simplicity that had shaped Clarissan and Franciscan architecture in the preceding generation. The nave pillars (pilastri delle navate) that defined the arcade were the structural spine of this arrangement: they bore the weight of the arcade arches and, above the arches, the load of the clerestory wall and the vault or timber roof of the central nave. The flanking aisles, lower than the nave, would have been covered by simple vaulting — groin or barrel — whose thrust was absorbed by the outer perimeter walls. The building’s spatial experience was one of modulated complexity: the arcade creating a visual and spatial rhythm through the nave, the aisles providing lateral extension that enriched the central space without competing with its directional pull toward the altar.

The Franciscan Observants who received the complex in 1444 brought with them an aesthetic of reformed religious life that valued spatial clarity, open preaching space, and visual access to the choir and altar. The mendicant tradition in general — and the Observant reform within it — favored unified interior spaces over the compartmentalized arrangement of the Romanesque basilica. The decision to demolish the nave pillars was both a structural and a liturgical statement: by removing the arcade supports, the builders opened the interior into a less segmented space where the congregation could more directly relate to the liturgical action in the choir beyond.

The grandi archi a sesto acuto — the large pointed arches that replaced the arcade — are the most visible structural consequence of this decision. These arches span the full width of what had been the nave plus aisle space, connecting the perimeter walls at a height that rises well above the former arcade level and that generates a very different interior spatial experience: dramatic vertical development on the structural arches themselves, rather than the lateral horizontal development of the arcade. The pointed arch form was structurally advantageous for this purpose: its greater height-to-span ratio generates less lateral thrust than an equivalent semicircular arch, and in a construction where the perimeter walls were the only available abutment, reducing thrust was directly equivalent to structural safety.

The side chapels added in this campaign modified the Romanesque bilateral symmetry of the three-nave plan. Where the Romanesque and Clarissan building had maintained a clear tripartite lateral organization — nave flanked by two aisles — the addition of chapels engaged with the outer perimeter walls introduced a lateral complexity that enriched the building’s spatial variety while disrupting the clarity of the original symmetrical arrangement. This move was characteristic of late medieval Franciscan architecture in the Lombard region, where the demand for private masses and chapel endowments by noble families required additional altar spaces that could not be accommodated within the original Romanesque spatial program.

The creation of a distinct presbytery and choir area — architecturally separated from the nave by the demolition of the intermediate pillars and the raising of the large arches — produced a space organized more by the distinction between nave and sanctuary than by the multiplication of lateral units. The choir functioned as a reserved space for the community’s liturgical life, while the enlarged nave served the pastoral functions that the Observants’ preaching mission required. This spatial reorganization was a Gothic spatial solution to a Franciscan functional need, implemented within the structural constraints of a Romanesque and Clarissan building.

Structural Consequences: Load Paths, Thrust Distribution, and Wall Response

The structural drama of the 1470-1500 campaign — the removal of intermediate supports and the introduction of large spanning arches — had consequences for load distribution throughout the building that the existing structure had to accommodate. Tracing these consequences through the structural logic of the building illuminates why the thick Romanesque wall was not merely preserved but actually enhanced in value by the Gothic intervention it was asked to support.

When nave pillars are removed from a basilican structure, the loads that those pillars formerly carried must find new paths to the ground. In the original Clarissan arrangement, each pillar carried the concentrated load of the arcade arches converging at its capital, plus the point loads of vault ribs descending from the bays above. These concentrated loads were transferred through the pillar shaft directly to the foundation: a clear, short structural path. When the pillars were removed and spanning arches substituted, the loads were redistributed: instead of concentrated point loads at the former pillar positions, the new arches delivered their loads at the perimeter walls — at the springing points where the arch bases met the wall face.

This redistribution demanded that the perimeter walls be adequate to absorb not only the vertical component of arch thrust (the dead weight of the arch carried in compression) but also the horizontal component — the outward push that any arch generates at its haunches. The pointed form of the new arches reduced but did not eliminate this horizontal thrust: the steeper the arch, the smaller the horizontal component relative to the vertical, but as long as any arch departs from true verticality at its springing (which all arches must do to span a horizontal distance), horizontal thrust exists.

The Romanesque perimeter walls were adequate to these demands precisely because they had been built with the generous thickness required to resist the thrust of an earlier vault system. When the 1256-1265 builders retained and reinforced the perimeter walls of the earlier structure, they inadvertently provided a structural reserve that the 1470-1500 builders could draw upon. The wall mass that was a direct product of Romanesque structural philosophy — built thick because that was the Lombard way of managing vault thrust — was exactly the structural asset that a Gothic arch system needed in the absence of external buttresses. San Nazaro della Costa’s structural history is therefore a case of Romanesque prudence enabling Gothic ambition: the thick walls of one tradition creating the conditions of possibility for the structural boldness of the next.

The addition of side chapels along the perimeter walls introduced further structural complications. Each chapel opening required a breach in the perimeter wall — an arch or flat lintel cutting through the wall thickness to connect the nave space with the chapel beyond. These openings reduced the effective mass of the wall at the points of chapel connection, and the chapel arches added their own modest thrust to the forces acting on the wall. The careful placement of chapels between rather than at the arch springings — respecting the positions of maximum thrust concentration — suggests that the 1470-1500 builders understood the structural constraints and worked within them with deliberate spatial intelligence.

Volumetric Symmetries: Proportion, Geometry, and Compositional Equilibrium

The concept of volumetric symmetry in architecture refers to the three-dimensional balance of spatial masses — not the flat bilateral mirror symmetry of a facade, but the dynamic equilibrium among volumes of different scale, height, and function that gives a building its sense of compositional order. In the Lombard Romanesque tradition, this equilibrium was achieved through proportional systems whose exact mathematical basis has been the subject of extensive scholarly debate but whose practical effect is visible in the harmonic quality of the best buildings of the tradition.

The fundamental volumetric equation of the Lombard basilica is the transverse section: the relationship between the height and width of the central nave and the height and width of the flanking aisles. In the buildings of the great Lombard Romanesque tradition — Sant’Ambrogio in Milan, San Michele in Pavia, San Zeno in Verona — this relationship approaches but rarely achieves pure mathematical ratios. The nave height runs between one and a half and twice the aisle height; the nave width is between one and a half and twice the aisle width. These proportions, maintained consistently from the floor plane upward through the arcade to the vault, produce the visual experience of the nave as a dominant volume with subsidiary volumes in attendance — a hierarchical spatial arrangement that the liturgical organization of the space reinforces: the nave for the congregation, the aisles for lateral movement, the sanctuary for the clergy.

The ad quadratum proportional system — in which each successive spatial unit is generated by rotating the diagonal of the preceding square — appears consistently in Lombard Romanesque bay proportions. A square bay plan, when its diagonal is rotated to become the new side, generates a larger square in a ratio of 1 to the square root of 2 (approximately 1 to 1.414). This ratio governs not only plan geometry but section: the diagonal of the nave plan bay, when rotated upward, generates the nave vault height in a consistent application of the same proportional rule. The result is that a building organized by the ad quadratum system presents proportional harmony in plan, section, and elevation simultaneously — a three-dimensional volumetric coherence rather than a two-dimensional compositional order.

The longitudinal axis of the Lombard basilica generates a different and complementary volumetric symmetry: the directional progression from the entrance wall through the nave to the apse. The apse — a hemispherical termination of the central nave volume — is the formal and liturgical destination of the building’s longitudinal axis. As a volume, it relates to the nave in two ways: it provides a terminus that arrests the directional movement of the nave (the cylindrical apse wall halts the horizontal thrust of the nave space) and it introduces a curved surface that mediates between the flat geometry of the nave walls and the hemispherical geometry of the apse vault (a conch vault, a quarter-sphere surface that softens the corner between the apse wall and its ceiling). The apse’s volumetric relationship to the nave is that of a terminal equilibrium: the building’s directional energy culminates in a volume whose rotational geometry stands in productive contrast to the rectilinear longitudinal nave.

At San Nazaro della Costa, the volumetric symmetries of the Romanesque plan were partially disrupted and partially maintained by the subsequent campaigns. The three-nave symmetry — nave flanked by equal aisles — was preserved in plan through the 1256-1265 rebuilding and, despite the pillar demolition, through the 1470-1500 transformation. The addition of side chapels introduced asymmetric lateral projections, but these were positioned with sufficient regularity to maintain a degree of bilateral order in the nave plan. The creation of a distinct presbytery and choir zone — architecturally differentiated from the nave by the large pointed arches — introduced a new longitudinal inflection: the building now reads, in volumetric terms, as a nave volume enclosed by large Gothic arches followed by a presbytery volume of different spatial character, with the apse as ultimate terminal. This sequential volumetric organization — nave, presbytery, apse — is richer and more articulate than the simpler Romanesque sequence it replaced, but it operates within the same axial and bilateral symmetrical framework that the Romanesque plan established.

The Fresco Environment: Pictorial Programs and Structural Surfaces

The fresco cycle of San Nazaro della Costa is inseparable from the architectural history of its walls: each phase of pictorial decoration is also a record of the structural surface on which it was applied, and the sequence of campaigns from the thirteenth century through the late fifteenth constitutes a painted stratigraphy that parallels and partially illuminates the building’s architectural development. Fresco technique — the application of mineral pigments in water to wet lime plaster (arriccio plus intonaco) bonded to the brick substrate — is architecturally intimate in a way that panel painting or mosaic is not: it cannot be separated from the wall without destruction, and the condition of the wall inevitably conditions the condition of the fresco.

The earliest pictorial element to survive, the thirteenth-century Deposition of Christ located at the head of the right nave, belongs to the period of the Poor Clares’ rebuilding campaign. Its position — at the terminal wall of the right aisle, facing the entrance from the nave — suggests a Clarissan devotional program organized around the primary visual axis of the nave while providing a subsidiary devotional focus for the laypeople who occupied the nave space. The iconographic subject — the Deposition, the moment of descent from the Cross — carried strong Franciscan and Clarissan resonance: the meditation on the suffering and death of Christ was central to the spirituality of both orders as articulated by Francis and Clare, and the choice to place this image at the head of the nave’s devotional secondary axis reflects the community’s spiritual priorities translated into spatial organization.

The decorations attributable to the Giottesque school, executed between 1330 and 1340, represent the penetration of central Italian pictorial innovation into the Novarese cultural sphere. The Giottesque revolution — the introduction of spatial depth, volumetric figure modeling, and narrative coherence into Italian painting through the Paduan and Florentine workshops of Giotto di Bondone and his followers — had reached the Po Valley by the second quarter of the fourteenth century, carried northward through commercial and ecclesiastical connections. The appearance of Giottesque-style frescoes at San Nazaro della Costa indicates that the Novarese community was engaged with contemporary artistic developments in central Italy, rather than remaining within a purely local pictorial tradition.

The attribution of the 1346 cycle to Giovanni da Milano — identified in the sources as Giovanni Jacobi di Como — is significant for the building’s art-historical position. Giovanni da Milano was among the most accomplished painters working in the Lombard and broader Italian artistic sphere in the mid-fourteenth century, and his presence at San Nazaro della Costa suggests that the complex maintained the patronage connections necessary to attract an artist of this caliber. Giovanni’s work, known from major commissions in Florence (the frescoes of the Rinuccini Chapel at Santa Croce) and Lombard sites, fuses the spatial intelligence of the Giottesque tradition with a northern sensitivity to surface texture and color that is characteristic of the Lombard-Italian cultural borderland in which Giovanni was formed.

Giovanni Antonio Merli’s Sant’Antonio da Padova of 1474 belongs to the transformed building — the interior reshaped by the Franciscan Observants’ structural campaign had just begun or was about to begin — and participates in the Franciscan iconographic program appropriate to an Observant community. Sant’Antonio of Padua was one of the most widely venerated Franciscan saints of the fifteenth century, and his representation in the church of a Franciscan community is both devotionally appropriate and iconographically standard for the period. The stylistic character of Merli’s work situates it within the Lombard pictorial tradition of the mid-fifteenth century: an idiom shaped by the Milanese court culture of the Visconti and early Sforza periods, where Lombard naturalism intersected with Flemish influence brought through the Alpine trade routes.

The late fifteenth-century Crucifixion in the apse catino and the Annunciation in the second right chapel complete the pictorial program as it stood at the close of the major structural campaigns. The placement of the Crucifixion in the apse is standard for the period and the building type: the crucified Christ in the terminal position of the church’s major axis provided the culminating visual focus for worshippers in the nave. The Annunciation in a lateral chapel space — the second right chapel — followed a common late medieval devotional pattern in which individual chapels received iconographic programs appropriate to the saints or mysteries they were dedicated to. Together, these late fifteenth-century frescoes complete a pictorial environment that spans two and a half centuries of devotional image-making applied to, and dependent upon, the architectural surfaces that the building’s successive structural campaigns produced.

San Nazaro della Costa in the Novarese and Padane Heritage Context

San Nazaro della Costa does not stand alone in the Novarese heritage landscape: it is one node in a web of ecclesiastical monuments that together define the architectural culture of a city that occupied a significant position in the Lombard medieval world as a bishop’s see, a commercial center on the routes between the Po Valley and the Alpine passes, and a point of contact between the Lombard tradition proper and the Piedmontese cultural sphere that distinguished Novara’s position from that of cities further east.

Within Novara itself, the Baptistery — a late antique structure with medieval modifications that represents the oldest continuously used architectural space in the city — and the Duomo complex provide the primary reference points for understanding the Romanesque and medieval building culture within which San Nazaro della Costa operated. The Baptistery’s construction and modification history spans the fifth through the twelfth centuries, making it a document of the transition from late antique to Romanesque in the Novarese context — precisely the transition whose early phase produced the tenth-century precursor at San Nazaro della Costa. The Duomo’s Romanesque phases, subsequently transformed in the nineteenth century by Alessandro Antonelli whose cupola for San Gaudenzio dominates the modern city’s silhouette, provided a canonical local example of the Lombard basilica type against which suburban and extra-mural churches necessarily measured themselves.

The parallel case of the fortified abbey of San Nazzaro Sesia — dedicated to the same saints and located in the same ecclesiastical province — illuminates the Lombard brick tradition at a moment of greater survival: at San Nazzaro Sesia, the Romanesque campanile of circa 1050 survives substantially intact, with its characteristic square section, six articulated registers, and rows of archetti pensili, providing an example of precisely the Lombard tower typology that the campanile at San Nazaro della Costa would have belonged to. The 35-meter campanile at San Nazzaro Sesia, built in a combination of stone at the base and brick in the upper sections, and the Gothic church rebuilt in the fifteenth century under abbot Antonio Barbavara, present an almost exactly parallel history to San Nazaro della Costa — Romanesque tower and structural fabric, Gothic rebuild in the fifteenth century — making the two complexes natural comparative objects for the study of the Novarese architectural tradition.

Beyond the immediate Novarese context, San Nazaro della Costa belongs to the broader family of northern Italian Franciscan and Clarissan churches whose architectural development responded to the reform movements of the thirteenth through fifteenth centuries. The Poor Clares’ tradition of modest basilican construction — three naves, simple vaulting, painted rather than carved decoration — and the Franciscan Observants’ tradition of open preaching spaces together shaped the building’s spatial history in ways that connect it to a network of mendicant architecture extending from Assisi and Florence northward through Lombardy and Piedmont. The Lombard brick medium gave local expression to spatial and liturgical programs that were the product of reforming traditions originating far beyond the Po Valley.

Paolo Verzone’s fundamental study of Vercellese Romanesque architecture, and Antonio Aina’s more focused work on the Novarese built heritage, established the scholarly framework within which San Nazaro della Costa’s architectural significance has been understood by the Italian heritage community. The preservation of the building under Capuchin stewardship since 1929 — following the period of progressive decay after 1810 — and the municipality of Novara’s 1923 initiative to promote its artistic recovery, represent the institutional framework within which the building has been maintained and interpreted. The Museo storico novarese “Aldo Rossini,” inaugurated in 1965 adjacent to the church, integrates the site within the civic memory of the city’s military history while preserving the architectural and artistic context from which that memory is inseparable.

Conservation, Stewardship, and the Building’s Present Condition

The conservation history of San Nazaro della Costa in the modern period follows a pattern common to many extra-mural religious complexes in northern Italian cities: institutional dissolution, progressive decay, administrative recovery, and eventual institutional stabilization under a new religious or civic custodian. The cycle that brought the building to its current state began with the departure of the Reformed Franciscans in 1810 — a consequence of the Napoleonic suppressions that emptied hundreds of Italian convents and monasteries — and continued through a period of unclear ownership and maintenance responsibility in which the complex passed to the Ospedale Maggiore of Novara.

The municipality of Novara’s 1923 initiative to promote the complex’s artistic recovery was the decisive turning point. Institutional recognition of the building’s architectural and pictorial significance created the political conditions for the 1928 convention between the Ospedale Maggiore and the Capuchin Friars of Alessandria, under which the Capuchins took responsibility for the complex’s care and religious life. The Capuchin community that has inhabited and managed San Nazaro della Costa since 1929 provides the continuous human presence that physically maintained ecclesiastical buildings require: regular use is itself a form of conservation, maintaining humidity regulation, identifying deterioration, and ensuring that structural problems are noticed before they become irreversible.

The restoration and restructuring campaign of 1928-1929 that accompanied the Capuchin installation was a comprehensive intervention that addressed the most critical conservation needs while establishing the building in its current form. The commistione — the characteristic mixture — of architectural elements from different periods that the building now presents is not a failure of conservation coherence but an honest reflection of the building’s layered history: the Gothic pointed arches, the Renaissance facade windows and portico, the Romanesque structural legacy in the wall mass. Conservation of a building with this degree of historical complexity requires decisions about which layers to retain, which to reveal, and which to allow to coexist without interpretive hierarchy — decisions that the 1928-1929 campaign made in ways that subsequent assessment has largely confirmed as appropriate.

The colle della Vittoria’s dual function as Parco delle Rimembranze — the Park of Remembrances, commemorating Novara’s war dead from 1848 to 1945 — integrates the architectural monument within a landscape of civic memory that gives the site multiple and simultaneous meanings. The Museo storico novarese “Aldo Rossini,” inaugurated adjacent to the church in 1965, extends this commemorative function while placing it in the physical proximity of the medieval religious monument whose construction preceded the commemorated events by six or more centuries. This juxtaposition — medieval religious architecture and modern civic commemoration sharing a hilltop outside the city — is characteristic of the complex layering of Italian memorial landscape, in which different historical and functional strata occupy the same physical space without mutual exclusion.

The building’s significance for the study of Lombard brick Romanesque architecture is not diminished by the absence of preserved Romanesque fabric in visible surface form. On the contrary, San Nazaro della Costa presents something that a well-preserved Romanesque building cannot: the evidence of how a Romanesque structural logic persists through and enables subsequent transformations of a radically different architectural character. The thick walls that survived the Poor Clares’ rebuilding, the three-nave plan that persisted through the Franciscan Observants’ structural reorganization, the brick construction medium that continued through Renaissance interventions — these are the Romanesque elements that matter architecturally, not the pilaster strips and corbel tables that were never the building’s deepest structural identity. To read San Nazaro della Costa with architectural understanding is to recognize that the Lombard brick tradition lives not in surface ornament but in the material intelligence of construction that makes every subsequent layer possible.

Frequently Asked Questions About the Abbey of San Nazaro della Costa

When was the Abbey of San Nazaro della Costa founded?

The complex’s origins predate its surviving documentation. A church dedicated to Saints Nazarius and Celsus existed on the colle della Vittoria outside Novara’s city walls from at least the tenth century, with the earliest surviving documentary attestation dated 1124 and a second cluster of records from 1155 to 1157. The three-nave basilican church whose spatial logic the building still follows was constructed between 1256 and 1265 by the Poor Clares of San Pietro di Cavaglio, who also established the adjacent convent. The complex is therefore a foundation in successive phases rather than a single founding moment.

Who were the maestri comacini and what role did they play in Lombard brick construction?

The magistri comacini — master builders associated with the lakes district around Como — were the principal bearers of the Lombard constructive tradition that shaped church architecture across the Po Valley and beyond from the ninth century onward. Their knowledge included brick-firing and laying techniques, vault construction methods, the vocabulary of pilaster strips and corbel tables, and the proportional systems used in organizing basilican plans. Their expertise was portable and proprietary, carried through networks of builders who traveled from commission to commission across Lombardy, Piedmont, and further into France, Catalonia, and the Rhineland. The architectural vocabulary they diffused — the lesena, the archetti pensili, the tiburio, the square campanile — became the recognizable signature of the Lombard Romanesque tradition across a vast geographic area.

What is a barrel vault and how does it function structurally?

A barrel vault is a continuous semi-cylindrical vaulted ceiling formed by extruding a semicircular arch along the length of a nave or room. Its structural action is that of an extended arch: it converts gravity loads (the weight of the vault itself plus overlying materials) into oblique compression directed along the vault surface toward the supports. At the base of the vault, where it meets the supporting wall or pier, this oblique compression divides into a vertical component (downward, carried safely in compression through the support) and a horizontal component (outward, constituting lateral thrust). This outward thrust must be absorbed by the perimeter walls, which must be thick enough to resist deflection, or by flanking volumes that provide counter-thrust. The management of barrel vault thrust — through massive walls, flanking aisles, or external buttresses — was the central structural challenge of Romanesque church design.

What is a lesena in Lombard Romanesque architecture?

A lesena (plural: lesene) is a flat pilaster strip — a shallow rectangular projection bonded into the external wall surface of a Lombard Romanesque building at regular intervals corresponding to the interior bay system. Unlike a classical pilaster, which has a capital and base and projects significantly from the wall, the Lombard lesena projects one brick width from the wall face. It serves both a structural and an expressive function: structurally, it increases local wall thickness at the points where transverse arch loads bear on the outer face; expressively, it articulates the wall surface into a rhythm of vertical accents that reads the interior bay system on the exterior. The lesena terminates at the corbel table level, establishing the visual connection between vertical and horizontal articulation elements that characterizes the Lombard Romanesque wall system.

Who created the frescoes in San Nazaro della Costa?

The fresco program of San Nazaro della Costa spans multiple campaigns across two and a half centuries. The thirteenth-century Deposition of Christ at the head of the right nave was executed in the 1256-1265 period of the Poor Clares’ rebuilding. Decorations attributable to the Giottesque school were added between 1330 and 1340, followed by a 1346 cycle attributed to Giovanni da Milano (identified as Giovanni Jacobi di Como), an accomplished painter whose work is also documented in Florence and Lombard sites. Giovanni Antonio Merli painted the Sant’Antonio da Padova in 1474. The late fifteenth century added the Crucifixion in the apse catino and an Annunciation in the second right chapel. The IHS monogram, the Franciscan Observant emblem popularized by San Bernardino da Siena, appears throughout both church and convent from the Observant period onward.

What is the difference between a groin vault and a barrel vault?

A barrel vault is a continuous semi-cylindrical surface, generating continuous lateral thrust along its full length. A groin vault is formed by the intersection of two barrel vaults at right angles: the lines of intersection (the groins) create diagonal ridges that divide the vault surface into four concave triangular panels. The structural advantage of the groin vault over the barrel is the concentration of load: where a barrel vault distributes its thrust uniformly along the length of the supporting wall, a groin vault concentrates its forces at the four corners of the bay, where the groins touch their supports. This concentration allows the wall sections between corner supports to be thinned or opened, and makes it possible to support the vault on isolated columns or piers rather than on continuous wall masses. Groin vaults covered the aisles while barrel vaults spanned the naves in early Lombard Romanesque construction.

What happened at San Nazaro della Costa when the Franciscan Observants took over in 1444?

The transfer of the complex to the Franciscan Observants in 1444, effected by Bishop Bartolomeo Visconti of Novara, initiated the period of greatest architectural transformation. The Observants’ reforming ethos valued open preaching space and clear visual access to the choir, preferences that motivated the major structural campaign carried out between 1470 and 1500. During this campaign the original nave pillars were demolished, the presbytery and choir space was reorganized, large pointed arches were raised to span the width of the former nave and aisle space, and side chapels were constructed along the perimeter walls. The monogram IHS — associated with the Observant movement through San Bernardino da Siena’s preaching campaigns — was incorporated into the decorative program throughout the church and convent, physically inscribing the Observant identity into the building’s surfaces.

What are archetti pensili and what is their function on Lombard Romanesque buildings?

Archetti pensili (literally, “hanging small arches”) are corbel tables — rows of small arches supported on projecting corbel brackets that run along the eaves of a Lombard Romanesque building. They are among the most immediately recognizable features of the architectural tradition, appearing on campanili, apse exteriors, nave walls, and facades across the Po Valley and far beyond in buildings influenced by the Lombard tradition. Their primary decorative function is the definition of a rich shadow-line at the wall’s upper boundary, creating visual terminus to the pilaster strip articulation below. Their structural functions are secondary but real: the corbel projection delivers the roof load outward from the wall face, contributing to the overturning stability of a wall under lateral vault thrust, while the corbel table’s mass adds weight at the wall’s outer edge. The architectural refinement of archetti pensili — in the number of arches per bay, the depth of corbel projection, the decoration of corbel faces — is one of the primary sites of local variation within the Lombard Romanesque tradition.

How did the transformation of 1470-1500 change the structural character of San Nazaro della Costa?

The 1470-1500 transformation fundamentally altered the building’s structural logic from a pier-supported arcade system to a large-span arch system bearing directly on the perimeter walls. The demolition of the nave pillars removed the intermediate vertical supports that had defined the structural skeleton of the 1256-1265 church, redistributing their loads to the perimeter walls at the springing points of the new pointed arches. The grandi archi a sesto acuto — large pointed arches — generated less lateral thrust than equivalent semicircular arches would have done (the pointed form’s steep geometry reduces the horizontal component of arch thrust relative to the vertical), but still demanded that the perimeter walls absorb significant horizontal forces without deflection. The Romanesque-era wall thickness, inherited from the earlier building campaigns and preserved through the successive rebuildings, provided exactly the abutment mass the new arches required — a structural legacy of the Lombard brick tradition enabling a Gothic structural ambition that the tradition did not itself generate.

What is the current function of the Abbey of San Nazaro della Costa?

The complex has been inhabited and managed by the Capuchin Friars of Alessandria since 1929, under a convention established in 1928 between the Capuchins and the Ospedale Maggiore of Novara that then held the property. The church of Saints Nazarius and Celsus remains active as a place of worship. The hilltop on which the complex stands functions as the Parco delle Rimembranze, a memorial park commemorating Novarese war dead from 1848 to 1945. Adjacent to the church, the Museo storico novarese “Aldo Rossini,” inaugurated in 1965, preserves and presents the military memory of the city and its province. The complex thus combines active Capuchin religious life with civic commemorative functions and heritage tourism in a layering of contemporary uses that reflects the multiple historical strata of the site itself.

The Brick Romanesque: Volumetric Symmetries and Vaulting Mechanics in the Abbey of San Nazaro della Costa in Novara Piedmont

The Brick Romanesque: Volumetric Symmetries and Vaulting Mechanics in the Abbey of San Nazaro della Costa

People Also Ask About San Nazaro della Costa and Lombard Brick Romanesque Architecture

What distinguishes Lombard Brick Romanesque architecture from other regional Romanesque traditions?

How do barrel vaults generate and transmit structural thrust in brick construction?

What is meant by volumetric symmetry in the context of a Lombard Romanesque basilica?

How did the rebuilding campaigns of the thirteenth and fifteenth centuries alter the Romanesque character of San Nazaro della Costa?

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