Departures and Arrivals: From the City of Malleable Concrete to the City of Steel Frame

A few years after permanently relocating to the United States, Candela makes a devastating observation about the profession of architecture as it is practiced in his new home country and particularly in the city of his residency. When asked if his professional activities are harmed by his unwillingness to obtain American citizenship, Candela replies: “You can’t practice professionally here unless you have a very large firm. The two or three main offices here in Chicago have 600 to 800 people. I’m not interested in competing with them, plus I’m not trained for that.”¹ While, at first, this might appear like a tantrum by a disgruntled architect who was not able to secure commissions in his new home city, at closer inspection, these harsh words reveal an apt understanding of the changing dynamics within the field. Possibly, only a foreigner with a perspective like Candela was able to see how US architecture was dramatically altered during this time by the growth and commercialization of architectural offices, the resulting lack of experimentation in these firms, and the emerging cogency of general contractors as an all-encompassing gravitational force.

That does not fully explain Candela’s vehement criticism, however. After all, having designed an astonishing 1,437 projects up to that point and building close to 500 of them, Candela’s company was far from small. Cubiertas Ala (wing roofs), as it was poignantly called, performed services as an architecture studio, engineering firm, and contracting business, not only employing staff in its Mexico City-based office but also up to 600 laborers on different building sites.² This suggests that Candela’s comments were provoked by more than the scale of Chicago’s architecture operations. And the remainder of the interview implies as much. Asked if his inability to work in Chicago is related to the city’s “mostly vertical” construction, Candela simply responds: “It is that to some extent, and it’s also because those kinds of structures have gone ‘out of style.’ There used to be an interest in building them here. People would even travel to Mexico to see what we were doing, and they’d try to replicate it. Today, that field is practically dead here.”³ Apparently, recent changes in the way architecture was practiced in the US had irreparably altered the field and, ultimately, ended it. Beyond the quantifiable metrics of architecture firms, Candela objected to the way these large offices related to the practice, affected its trajectory, altered the figure of the architect, and transformed the discipline’s relationship to adjacent domains.

Therefore, an examination of Candela’s engagements with the US and his Chicago period from 1971 to 1978, reveals as much about his work during this time as it does about the constellations that enabled Candela’s experiments in Mexico, promoted his later departure, facilitated his transition to Chicago, and ultimately hindered his practice there. While his time in Chicago is hardly discussed and, if at all, only in passing, his relationships and frequent visits to the city and its institutions, coupled with his understanding of its architectural history and building culture, gave rise to high expectations for his eventual move to the Midwest. His engagements with and, ultimately, disarming realizations about Chicago are not just revealing about Candela’s late period, they also give illuminating insights about US architecture practice.

Admiration: Chicago’s Fascination with the “Wizard of the Shells”

Reminded of the frequent visits by US architects and engineers, contractors, and organizations to his office in Mexico City and his numerous buildings across the country during the 1960s, Candela viewed the changes in Chicago’s architectural culture as recent. Indeed, Mexico City and Candela’s buildings in particular, were pilgrimage sites for Northern American architects.

Brigitte Peterhans—designer and later Associate Partner at the Chicago office of Skidmore, Owings & Merrill (SOM)—for example, reported on her travels through Mexico and her visits to buildings by Candela in the early 1960s. Interestingly, she understood these visits as research on figures and offices that SOM used to measure itself. As part of the Art Institute of Chicago’s Architects Oral History Project, interviewer Betty J. Blum asks: “Who were SOM’s biggest competitors?” to which Peterhans replied, “Early on there were Dinkeloo and Roche, Philip Johnson and Saarinen. From a distance we all adored Luis Barragan and Félix Candela in Mexico. When I traveled through Mexico in 1962–1963 Bruce Graham made me visit both.”⁴ Apparently, Graham, a lead architect at SOM and mastermind behind works such as the Inland Steel Building and later the John Hancock Tower, had instructed her to visit the work of Candela and Barragan and possibly even the architects themselves, likely in an effort to inform the work at SOM once she arrived back in Chicago. While she did not return until several years later, Peterhans was certainly able to judge Candela’s prominence in US architecture offices even without Graham’s suggestion. In 1957, she came to the Illinois Institute of Technology (IIT) from the University of Stuttgart on a Fulbright scholarship to study with Mies van der Rohe. She began work at SOM while still a student and kept in close contact with her brother Jörg Schleich, an internationally known structural engineer of bridges and long-span roofs.⁵ With that background, Peterhans was well equipped to recognize the constellation of affinities between SOM’s ambitions and Candela’s achievements. Her report supports Candela’s claim that Chicago offices were eager to learn from his work.

The interest was not limited to Chicago. The Home section of the Los Angeles Times, for example, reported in 1960 that “Mexico City buildings [are] so advanced that architecture has become a foremost tourist attraction.”⁶ The article focuses solely on Candela’s work, recognizing the singular position of his forms in concrete and suggesting that his single-handed transformation of Mexican architecture alone is worth a visit to the capital, while celebrating it as highly innovative. Making note of the structural advancements in the work, the article foregrounds the spatial and formal effects. “Now the plasticity of concrete is finally being exploited,”⁷ the article concludes, using a phrase that is likely indebted to the 1957 exhibition and catalog Felix Candela: Shell Forms by Esther McCoy at the University of Southern California, Los Angeles.⁸ The architectural historian McCoy, who later would become known as the author who introduced California modernism to a wider audience, had also lived in Mexico, became friends with Candela, and was a passionate admirer of his work.⁹ The exhibition was an early introduction of Candela’s concrete shells to an audience interested in experimental form and the economy of concrete.

The construction industry, and certainly concrete contractors, were equally enamored by Candela’s forms and building operations. A tour of his construction sites in Mexico was the “highlight of the annual meeting held […] in Houston, Texas, by the National Concrete Contractors Association,” as we read in the 1964 issue of the trade journal Concrete Construction.¹⁰ For members of this US-based organization, the most treasured experience was not the conference itself but the post-convention field trip to Candela’s building sites. Understandably, this party of contractors and engineers was most captivated by two aspects of his work. They foregrounded Candela’s multidimensional practice: “more than just an architect” as they wrote, he “conceived and built” these structures, and they were mesmerized by the magnitude of his activities “building more than 8 million square feet of concrete umbrellas in the past five years alone.”¹¹ Not only did they see Candela as a fellow contractor, acutely aware of the challenges of building, but they were also fascinated by the sheer scope of his reach. As Angela Giral has documented, Candela had cultivated relationships with US contractors and organizations that represented the construction industry since the 1950s.¹² As early as 1952, Candela published in the Journal of the American Concrete Institute and by the 1960s he was one of the most visible and recognized figures in the orbit of informed US-based contractors. One of the largest centers of the building industry, and a city where many companies where headquartered, was Chicago: originator of balloon construction, fundamental in the development of skeleton construction and wind bracing, leading in the evolution of reinforced concrete construction, home to companies such as Portland Cement, and by the 1940s also leading the charts with a record number of tall concrete buildings in North America.¹³

While the latter statistic might be surprising, given Chicago’s perceived preoccupation with steel frame, that dominance was less pronounced in the 1960s. The Chicago-based architectural historian Carl Condit, for example, writes about “The New Architecture of Chicago” in 1964, identifying “a deliberate return to the basic principle of the Chicago School, a direct statement through structure of the necessary physical character of the building.”¹⁴ And while this allusion to the so-called “First Chicago School” and its protagonists—from Henry Hobson Richardson to Daniel Burnham, Louis Sullivan, and Frank Lloyd Wright—might suggest a focus on the steel frame, Condit outlines that he sees a tendency “to exploit the potentially dynamic quality of the structural frame of steel and concrete.”¹⁵ Although concrete is mentioned, it might still come as a surprise that Candela would feature so prominently in the introduction and conclusion of this essay on Chicago. Condit opens by observing the “enthusiasm […] [toward] the leading 20th century innovations in concrete construction, especially thin shells” and cites Candela as its “foremost builder of such structures by virtue of the number, diversity, and daring shapes of his designs.”¹⁶ While in comparison to Mexico, very few thin-shell structures were undertaken in the US, Condit manages to list several, including the Edens Theater by Perkins & Will in the Highland Park suburb of Chicago (1963)—suggesting a clear influence of Candela on Chicago practice.¹⁷ The conclusion then spells out how he sees the new “Chicago School” divided into two camps (subjective self-expression vs. objective structural design), where the larger camp is under the “influence of engineers like Nervi and Candela.”¹⁸ Even though Condit’s predictions did not actually materialize, they are an indication of Chicago’s architectural climate in the 1960s. If his essay is any indication, then Candela was of utmost importance and a key reference point for Chicago architecture to the extent that one strand of the newly forming modes of operation in the city was directly oriented toward his practice.

What likely informed Condit’s view of Candela’s early impact on Chicago are his connections to the city’s architectural institutions that can be traced back to the 1950s, a decade of utmost productivity, both in terms of his professional work and academic recognition. After founding Cubiertas Ala in 1949, completing the Cosmic Rays Pavilion (Pabellón de Rayos Cósmicos) at the University City of the National Autonomous University of Mexico (Universidad Nacional Autónoma de México, UNAM CU), and presenting his work through lectures in Mexico City and the US, Candela was appointed professor at UNAM in 1953. In the year 1955 alone, he completed 53 buildings.¹⁹ Highly visible in academic and trade journals, delegates of institutions and organizations not only visited his buildings in Mexico but also invited him to speak and exhibit. A session on concrete shells at the Midwestern Concrete Exposition in February of 1955 likely constituted Candela’s first visit to Chicago and, in October of 1958, his work was shown there in an exhibition titled The Works of Félix Candela.²⁰

Organized by the University Art Gallery at the Undergraduate Division of the University of Illinois Navy Pier Campus, the exhibit might have been initiated during Candela’s visit to the university’s Urbana Champaign campus for the conference “Design in Architecture from Analysis to Completion” two years prior and was certainly similar in content to the Esther McCoy-organized exhibition Félix Candela: Shell Form at the University of Southern California the year before. The success of the first Chicago exhibition is indicated by the return of his work to the Navy Pier campus three years later, when his Concrete Shells by Félix Candela opened in April 1961. By this time, Candela had amassed a large portfolio of built works, which included the High Life Textile Factory (Fábrica de Trajes High Life), the Church of Our Lady of the Miraculous Medal (Iglesia de la Virgen de la Medalla Milagrosa), and the Bacardí Bottling Plant in Tultitlán (Planta Embotelladora Bacardí), as well as projects in Guatemala and Texas.

In contact with faculty members on the Navy Pier and Urbana campuses, his connection to Chicago grew during the coming decade. Only three years after his second exhibition at the Pier, Candela was to return for a lecture to a large audience at IIT’s Grover M. Hermann Hall, an event supported by the Graham Foundation for the Advanced Studies in the Fine Arts and addressed to students and faculty at IIT and the College of Architecture and Art at Navy Pier. The deans of both schools used the event to advertise their programs to the “Wizard of the Thin-Shell,” as Candela was introduced in announcements for the event, quoting an Architectural Forum article from 1959.²¹ He was not just scheduled to speak at the IIT campus but was also to meet with Walter Netsch, architect at SOM and designer of two projects that surely would have sparked Candela’s interest. Netsch loomed large during this trip. He was the architect of Hermann Hall, the first of two buildings not designed by Mies erected on the Mies van der Rohe-designed campus, and he was the planner of the recently designed University of Illinois at Chicago Circle (UICC). The latter constituted the new location for a much-expanded footprint of the Navy Pier campus in the city’s Near West Side. SOM completed Herman Hall in 1962, at which point the design of the massive UICC project was already in full swing.²²

Coincidentally, Candela’s visit to Chicago in October of 1964 aligned with the final phase of the first stage of construction before UICC officially opened. The project that encompassed over 100 acres was to become the only urban four-year publicly funded university in Chicago, a modern urban-grant institution with an education program that was to support contemporary industry and include a department of architecture. Accommodation for commuters was achieved through the immediate adjacency to a subway stop and the Circle Interchange—a colossal infrastructural concoction of two expressways, which also became the namesake for the university.²³It was via this infrastructure that Candela likely approached the campus for the first time, either coming from IIT’s southern location or from downtown to the northeast. From both directions, the elevated ramps of the circle would provide him with ample views across the campus—granting a first impression of the largest building effort in the city. University Hall, the only tower on campus that would eventually reach 28 floors, had already topped 17 stories, and the different lecture centers and administration buildings were well underway to open their doors to welcome the first class of students in February of 1965. In photographs from the tower, we see the interchange and the north-eastern corner of the campus, where the Architecture and Art Laboratories were eventually built.

Leading up to Candela’s Chicago visit, Leonard Currie, Dean of UICC’s College of Architecture and Art since 1962 (when it was still located at the Pier), organized a meeting between Candela and Netsch, who was eager to show off the UICC construction. Currie noted in a letter to the Director of the Architecture and City Planning Department at IIT, George E. Danforth: “I have written Felix suggesting that he have a tour of our new campus the following morning [after the lecture]… Walter Netsch says he will be glad to give Felix a conducted tour that (Wednesday) morning.”²⁴ This was just four months before the campus was to open. Apart from the tower, from which Netsch and Currie often took photographs of the progress of construction, the most ambitious part of the plan was the forum at its core.

The raised plaza on top of classroom buildings connected via elevated walkways to the different locations on campus, establishing a network that connected the numerous disciplines. The ground was left to greenery and a system of sidewalks surrounding buildings, giving way to a very different perspective, directionality, and speed of movement. As Currie described, you could “get to the pedestrian ramp, and go anyplace on this campus and never cross vehicular traffic.”²⁵ The forum, around which building groups were organized by function, was the nucleolus of this network that Netsch understood as a kind of contemporary agora and a place for the collective.²⁶ During Candela’s visit, the raised plaza was in place, the flooring work was prepared, and the supports for the sunken theater had been cast in place. One can imagine the two architects walking among the butterfly columns that would eventually hold the elevated walkways, and one can picture how the two made their way to the raised plaza on top of one of the classroom buildings.

On the one hand, Candela was no doubt skeptical of Netsch’s use of concrete, as he had frequently attacked the use of the material for trabeated systems, which in his view negated the true behavior of concrete.²⁷ On the other hand, the spatial implications, programmatic ambitions, and sheer scale of the project were surely noteworthy for Candela. In other words, the programmatic consequences of their very different concrete forms acted similarly. Candela’s undulating roof surfaces compressed and expanded occupiable space and, by doing so, gently steered the otherwise open-floor plan into zones. Netsch inverted Candela’s warped roof and created a differentiated walkable surface that encouraged different forms of inhabitation and action; as would be the case four years later, when the campus and the forum in particular became the battleground for student protests.²⁸ Both formulated an interstitial space that is neither inside nor outside. Netsch created different settings and urban rooms on a raised plaza, while Candela often imagined his roofs without any interrupted glazing or doors—essentially articulating a civic space that provided room for assembly and unprogrammed activities.

Dialog: Netsch, Mies, Goldberg, and Banham

Netsch was an outlier in the cohort of Mies-trained architects at SOM. Believing in material invention and formal innovation, he intentionally positioned his work as a counter to Miesian doctrine. The two campuses, IIT and UICC, could not be more different. And this surely did not escape Candela. Both respected Mies but saw their work as part of a new generation, eager to push the formal and material boundaries of architecture. Already in 1954, Candela openly criticized Miesian form in his lecture at the Massachusetts Institute of Technology (MIT). When arguing for the advantages of double-curved surfaces, whose form “will always be in equilibrium,” Candela used one of Mies’s most ambitious designs to show how architects “stubbornly persist[...] in building cubic shells.” Directing his criticism, Candela noted that this “is especially striking when such wasteful and extravagant structures are applied to cover huge spaces, as in the 700 feet square Convention Hall proposed for Chicago by Mies van der Rohe.”²⁹ For Candela, this was not just a structural concern or a simple critique of rectilinear form; it was a material and economic argument.³⁰ After all, most of Candela’s roofs had to conform to rectilinear footprints, but Candela rejected the use of planar geometry and instead deployed doubly curved surfaces for their thinness and structural integrity.

For him, those curvatures conformed to natural, almost instinctual, laws—principles, which, “routinely employed in other technical fields, as in the fabrication of car bodies, have been but reluctantly recognized and put to use in the building industry.”³¹With this assertion, Candela expands his argument to include notions of technological and material progress, in which architecture had fallen behind. By linking architecture’s hesitancy to Mies, Candela sets up a generational and technological divide, one which Reyner Banham, for example, identified between the first and second machine age. And, just like Candela before him, Banham links the moment of division from the first to the second generation to shifts in the use of curvatures in car bodies. As a caption for a series of car photographs, Banham writes: “The end of the First Machine Age in design can be demonstrated in its symbolic machine, the automobile. Gropius’ Adler, though handsome, is mechanically backward when compared with the streamlined, rear-engined harbingers of the next phase.”³²

Two years later, Banham’s chapter on “Construction” in The Age of the Masters, substitutes analogies for names. Associating hesitancy toward curvature with the previous generation of Le Corbusier and Mies, Banham singles out Candela as marker and maker of the “second revolution.”³³By focusing on the formwork, Banham argues that it was “Candela’s shuttering that really marked the epoch, because it had always been the argument from shuttering that was the last ditch defense of the rectangular framed structures which—literally—supported the rectangular uniform of teenage modern.”³⁴ Following Candela’s earlier argument and citing the Cosmic Rays Pavilion at UNAM, Banham notes the superior performance of concrete when multi-curved, which was only prevented by the difficulty and expense of curved formwork. Here, Banham traces the rectangular forms of modernism to construction processes and the basic economy of molds. Since these “were cheapest to make from straight planks, concrete would be square.” But “Candela showed that by picking the right geometric form [...] you could get complex three-dimensional curves out of simple plank shuttering.”³⁵ With that, Banham not only disarms the modernist myth that links concrete to a strict formal repertoire, but also projects a new course in which a novel combination of material and geometric intelligences brings about new form—one that Candela makes possible.

Indeed, the collision between the two manners of structural thinking come into sharp view in 1954. In the same year that Mies composed his collage for the Convention Hall, Candela wrote his critique of the project and built the High Life Textile Factory and the Río’s Warehouse in Linda Vista (1954), both located in Mexico City. Similar in their emphasis on the single roof as the predominant element that expands over a continuous floor, the enormous clear span of the Convention Hall gave Mies a large column-free interior, while Candela’s series of tilted concrete umbrellas provided ample light for the large expanse of a deep floor plan. In both images—the photograph of the warehouse in which we see Candela posing and the collage where Mies placed attendees from the 1952 US Republican Convention—the ceiling takes up more than half the page, emphasizing its importance. Mies’s deep two-way spanning system continues across the entire space through an undifferentiated steel-truss grid that heightens the scale of the hall; Candela’s differentiated, slightly slanting, and textured concrete plays with light that washes the surfaces. Both works are almost all roof, but whereas the Convention Hall celebrates a clear expression of the technical, geometrical, and material diagram of a structural steel grid, the Warehouse organizes a more intuitive and seemingly more complex model. For Candela, however, the warped surfaces were not considered more complex, but rather made for a highly economical use of the material and of space. In contrast, in the Convention Hall he saw enormous energy spent on spanning the space with a flat roof—an effort in which, according to him, the outcome did not justify the means. Interestingly, Candela singles out a project that scholars such as the late Detlef Mertins have identified as Mies’s “most un-Miesian” project.³⁶ And, perhaps, Candela was reacting to Mies’s adaptation of the space frame.³⁷

When he visited Chicago a decade after his critique of Mies, the Convention Hall had not been built but the concrete-saturated campus of UICC was under construction. It must have felt like a new dawn. And Netsch, who explained the campus design as they both strolled across the construction site, most certainly reinforced this image. “I never could be a Mies fan,” he once said. “I didn’t hold a line visually. Not like the box and variation of the box,”³⁸ by which he meant the Miesian formula of rectilinear volumes. Instead, Netsch searched for new kinds of geometrical patterns that questioned the singularity of the cube. Layering and rotating a multiplicity of squares “was the way we broke the box,” he noted, borrowing a phrase from an earlier well-known Chicago architect.³⁹ Netsch would generate hundreds of drawings to explore what he called the ordering system of “field theory,” which relied heavily on the basic square and the 45-degree angle as a factor to rotate and scale the squares in plan as well as to stack and grow them in section. This not only brought a new spatial dimension that could cultivate form in all directions, but it also presented a new structural integrity where rotating cubes balanced on each other vertically, creating cantilevers, openings, and terraces.

The Architecture and Art Laboratories building on the UICC campus was one of the earliest explorations of this technique. While construction for it commenced only after Candela toured the campus, Netsch was already deeply invested in his field theory and might have shared his ideas about the new building for the architecture faculty. Although his experimental geometry of repeating overlays and spinning squares has little in common formally with Candela’s hyperbolic paraboloids (hypars) created from straight lines, they both struggled to find escape velocity within a discipline still very much rooted in a modernist formal paradigm. Their work complicates architecture’s fixation with the cube. On the one hand, it appears complex, yet the techniques and technologies that generated those forms were disarmingly straightforward and their structural integrity surprisingly sound.

Joining Candela and Netsch in their search for an alternative geometry was Bertrand Goldberg—another Chicago architect—who was similarly critical of the architectural box. “By the end of World War I,” Goldberg wrote in retrospect, “the box was recognized as the perfect shape to package a right-angle society.”⁴⁰ With that, he was not just disapproving of its formal implications and limitations on architecture, but also indicated a possible confinement of society. Goldberg was Bauhaus and Mies-educated, revered Mies just like Netsch and Candela did, and would speak of him as a “surrogate father.”⁴¹ But, he also believed, “Gropius, Corbusier (until 1950), and Mies van der Rohe [...] were the romanticists who made the right angle a cult and who refined the expressions of the right angle architecturally into a creed.”⁴² Marina City, an endeavor that began at the end of the 1950s, was demonstrative of his tensions with the Miesian formal canon and affiliation with Candela’s geometry. The project integrated two 60-story residential towers with 19 floors of parking, a 16-floor office building with a bowling alley, a swimming pool, a theater, and a three-story podium that housed an ice-skating rink, stores, and a marina below. Candela, visiting the city in 1964, could not have possibly missed the building complex. Construction of the two towers had just been completed the year prior, and tenants had moved into the buildings that would become known as the tallest reinforced-concrete structures and tallest apartment buildings at the time. Marina City clearly stood out and became a symbol for Chicago, celebrating the city’s progress and American-based technological achievements. From Pan Am and Fleischmann’s Whiskey to Ebony magazine and Portland Cement, the towers would become the most widely viewed images for advertising Chicago and its businesses. The latter company provided the concrete for the building and recorded the construction process for a publicity film that appeared in 1965.

The film advertised the record-breaking construction speed of one floor per day on alternating towers, which was made possible through cranes that moved up as the construction of the cores advanced; the use of reinforcing mesh that meant less time for tying reinforcing bars; and polyester resin fiberglass molds that were reused as the work progressed. Both Goldberg and Candela recognized early on the consequential importance of formwork for the structures they were envisioning and became invested in not just the formal capacities of molds but also their economy. Goldberg seemed to have first experimented with fiberglass molds for the prefabrication of the kitchen at the Florsheim House in 1952, and the repetition of floorplate layouts at Marina City clearly called for the deployment of reusable formwork at a massive scale. The Portland Cement film, This Is Marina City elaborates how formwork was assembled in repetitive patterns on each floor, dismantling the forms on the finished floor, hoisting it into place three floors above, while leaving molds for drying attached to the floors below.

What became a vertical assembly line in Marina City, Candela had already envisioned for one of his roof structures in 1950. His article, “Cubierta prismatica de hormigon armado en la ciudad de Mexico” (Prismatic roof of reinforced concrete in Mexico City), speculated on the rapid movement of molds on tracks from one location to the next.⁴³ Of course, these clearly echo earlier modernist aspirations of transforming building sides into assembly lines: from Ernst May’s assembly method and Walter Gropius’s track system for Dessau-Törten in 1926 to Ernst Neufert’s house building machine in 1943. Yet Candela and Goldberg’s assembly of molds was unique and an indication of a rethinking of the characteristics and potentials of concrete—from prefabrication and on-site assembly to cast-in-place construction through reusable molds. At Marina City, molds were utilized on every floor, establishing a smooth connection between the flower-petal-shaped balconies, the carrying beams and branching columns, and the joining walls and slabs. For Candela, profiles could be repeatedly cast to compile the overall form of a roof. Fluid connections between different building elements were now built into the system and, in fact, presented the strength of the form.

While Candela ultimately produced his most celebrated structures using custom formwork, the end of the 1950s would see several projects in which reusable molds were deployed at a massive scale.⁴⁴ Interestingly, his most widely published and advertised projects in the US further capitalized on reusable molds in the Great Southwest Industrial District and the Texas Instrument semi-conductor building.⁴⁵For the former, a steel frame was covered with plywood and moved on wheels to sequentially grow the warehouse structure through umbrella shapes—forms that were additionally used for the entrance of a restaurant and the insignia of the industrial park. While the 1963 monograph that Candela produced in the office (written by Colin Faber) slightly mourns the lack of texture through the much smoother molds, the projects are also utilized to argue for shell structures in contexts where higher salaries and material costs might otherwise prevent it.⁴⁶ Texas Instruments even advertised the company’s technological advancement via Candela’s shells, arguing that the new building was not just a pleasant place to work but was also “designed for quick change or sudden growth [...] [that] derive[d] from two shapes used here for the first time industrially in the US. Concrete ‘umbrella-roofed’ bays form clear floor areas 63 ft. wide and up to 147 yd. long.”⁴⁷ Of course, the more elastic use of space and the predisposition toward expansion was always inherent in the Mexico-based umbrella shells, but the repetitive use of the same formwork contributed here to a new speed of construction and lowering of costs (through the reduction of manual labor and construction materials), making it appealing for use in the North. During the testing stage in 1956, one of the project architects reported to Candela: “the form system [...] erects easily and remounts easily and cheaply. At last, I think we are on the right track for using your structure here.”⁴⁸ With the seamless integration of shell construction in these large-scale projects, Candela must have been encouraged about a possible expansion of innovative concrete structures beyond Latin America. And witnessing the work of Netsch and Goldberg in Chicago during the 1960s clearly expanded the typological repertoire of concrete in North America beyond industrial buildings.

What these works have in common is an intimate understanding of the behavior of concrete, where advances in formwork facilitated high-performing concrete curvature. Even if Candela did not know of Goldberg before the 1960s, Marina City most definitely introduced him. The project was thoroughly documented in popular, trade, and architectural magazines at the time, and most certainly peaked Candela’s interest. Goldberg and Candela seem to have never mentioned each other, yet their fascination with curvature in concrete aligned since the mid-1950s. As Igor Marjanović and Katerina Rüedi Ray have shown, Goldberg’s attitude to concrete forms changed after he recognized varying load distributions between the center and the edge of a parking structure roof in 1957. Determined to find a more efficient form, Goldberg modeled a curved roof profile on a single leg that resembled Candela’s umbrella experiments. Although it does not reach the slenderness of its predecessor, both sections were propelled by considerations of efficiency and economy—aspects that for both architects would be common denominators in their justifications of certain forms and materials. Marina City was famously built for $10 to $12 per square foot, and the efficiency of Candela’s concrete shells was one of his main marketing tools, where industrial buildings could be constructed for an astonishing 50 cents per square foot.⁴⁹

In addition to the doubly curved diamond columns for the towers and the groin-vaulted space that holds the office block, the clearest formal reference to Candela was yet to emerge with the roof of the theater building that was finished 1967. Its first iteration came closest to Candela’s shells, as a hovering saddle-shaped concrete form was proposed. Obviously, the dramatic concrete ring beam that would have carried the weight of the concrete roof was based on a different structural ambition than Candela’s self-carrying concrete forms that thin-out at the edges. However, the formal ambitions, urban implications, and expressive effects are strikingly similar. Candela’s Open Chapel of Palmira (Capilla Abierta en Palmira), for example, has a similar saddle shape that rises high above the ground on one side before it swerves down and creates another opening on the opposite side. This structure avoids a heavy perimeter beam by minimizing its load through a thin concrete shell of only 1.5 inches; by giving the tall edge a small rim to reduce stresses; and by distributing the forces from the edge directly into the foundations.⁵⁰ Goldberg’s form, material, and structure for the roof changed throughout the design process. What was conceived as catenary steel cables with sprayed-on concrete was to be built with a system of triangulated steel beams below sprayed-on concrete and topped with lead cladding. The first iteration would have presented a true alternative to Candela’s formwork of straight wooden members but, in the end, was deemed too complicated and costly.⁵¹ Candela’s structural concrete curvatures might even have served as an initial model for Goldberg’s design, but a combination of local factors—from knowhow to the cost of labor—made the designed roof unfeasible.

The eventual decision to build the substructure of the curved roof out of standard steel beams is revealing as it exposes Chicago’s predisposition toward steel frame. The story of Goldberg’s roof and the failure of its initial design gives us a glimpse of the opposition that the context of Chicago mounted against complex curvatures in concrete and imparts a preview of the challenges that Candela would encounter when working in Chicago during the following decade. But, for the time being, Chicago and its massive building endeavors in concrete, coupled with a seeming openness to formal experimentation, must have shown a lot of promise in comparison to the challenges that his work faced in Mexico.

Reorientation: Years of Transition

In the second half of the 1960s, Candela’s connections to the US multiplied and solidified, while opportunities to practice his shell structures in Mexico diminished. Whereas his work might have been understood as one of the clearest incarnations of Mexico’s “miracle”—the country’s unprecedented period of economic growth that lasted until 1970—the end of this type of work naturally also came with the closure of that period. Luis M. Castañeda has vividly identified Candela as “the primary builder of Mexico’s economic ‘miracle’,” and his structures as a “‘Mexican’ architectural sensation.”⁵² His work not only represented Mexico’s technological advancements through seemingly impossible, miraculously thin concrete curves, it also housed the new industry and markets under endlessly cascading roofs that encouraged expansion.⁵³ All of this was made possible through his mastery of a material that since the early 20th century stood for Mexican progress and modernization. By fusing advanced architectural experimentation in curvature (the hyperbolic paraboloid as a structurally sound and aesthetically exuberant form) with low-tech building technologies (manual labor to build the formwork and to apply the concrete), Candela tapped a uniquely Mexican techno-economic condition.

One of the first US-based critics who clearly understood the Mexican-ness of Candela’s forms was Esther McCoy. Early on, she related Candela’s unique abilities with local conditions, economic constraints, and material preferences. “Mexico was a fortuitous place for Candela to experiment. It is receptive to the new [...] [a] handcraft country with an abundance of unskilled labor, it is responsive to concrete and hesitant with steel. The Shell is light in weight and therefore suited to the spongy soil of Mexico City.” And, she goes on to explain: “The hyperbolic paraboloid is especially practical and economical [...] [since] little reinforcing steel is required [...] [and it] can be formed by straight boards, which makes construction easily understood by unskilled labor.”⁵⁴ Of course, the workers that populated Candela’s construction sites were far from “unskilled,” as the history and ingenuity of Mexican craft documents. We should therefore augment McCoy’s statement by emphasizing the unique conditions of Mexico during the 1950s and 1960s, which saw coinciding the exceptional talents of the Mexican worker with the abilities of Candela. Mexico had become the ideal petri dish to culture thin-shell constructions. Inadvertently, this also delineated the climate that was needed to keep the equilibrium intact—aspects without which Candela’s work could not survive. One such requirement that reappears throughout McCoy’s article is “inexpensive labor.” Not only were the economics of Candela’s forms dependent on a large number of workers, but the geometry of the formwork and the technique to apply the concrete was also tuned to minimize complex workflows and machinery.

Interestingly, in the same year that McCoy published her article, these conditions were altered through the minimum wage decree of 1964.⁵⁵ In the coming years, the presidency of Gustavo Díaz Ordaz (1964-1970) brought a series of changes to Mexico’s economy that made Candela’s concrete shells increasingly costly. Salary for labor and material budgets for wood increased, aspects on which Candela’s work depended. In fact, these two components made the efficiencies of his concrete shells possible. The deployment of manual laborers who, in large numbers, packed the concrete by hand onto the formwork and the custom-made wooden molds that occupied all the space that would eventually be sheltered was responsible for creating the image of efficiency for Candela’s forms. In other words, the plentiful use of labor and material made the thin shell and the large span a reality. This dialectical relationship between the resulting form and the effort of production has been unearthed and tangibly described by María González Pendás as “two forms of economic imaginaries: performed efficiency and embodied excess.”⁵⁶ Once the dialectic was disturbed, as rising salaries and material costs called for a more embodied efficiency, Mexico’s legendary concrete thin shells performed much less proficiently. In addition, the process of shell construction as it was designed and executed by Cubiertas Ala not only relied on manual labor but its increasingly complex forms, coupled with rudimentary construction techniques, made for precarious working conditions that were prone to accidents.⁵⁷ As González Pendás has shown, this came into clear view once the Mexican Social Security Institute (Instituto Mexicano del Seguro Social, IMSS) began tracking these incidents through their labor risk assessments, which by the mid-1960s required Cubiertas Ala to pay mounting fines retroactively.⁵⁸ The shifting labor laws and a transforming economy would ultimately result in the demise of Cubiertas Ala in 1973, a date, however, by which Candela had long left the firm and settled in Chicago.

Candela’s reorientation from Mexico to the US took place between 1964 and 1968. It was roughly framed by the unfolding economic changes in Mexico (coinciding with his visit to the Circle Campus in Chicago) and the traumatic events of Mexico City’s ’68 student demonstrations and massacre, which ran parallel to the construction and opening of the Candela-designed Palace of Sports (Palacio de los Deportes) for the Olympic Games that same year.⁵⁹ The latter date constituted a complex series of events that impacted Candela personally. On the one hand, the Palace of Sports, designed by Candela, Antonio Peyri, and Enrique Castañeda Tamborell, became the focal point for the Olympic Games, a celebration of the progress of modern Mexico and an advertisement for successful governmental planning. On the other hand, the same government was also responsible for the killing of hundreds of unarmed students who were protesting an authoritarian government when Mexico’s police and military deployed ammunition and tanks to clear Tlatelolco Plaza just 10 days before the Summer Olympics.⁶⁰ Candela was not just in charge of the shimmering copper roof of the Palace of Sports, he was also responsible for his daughter, Antonia Candela, who was part of the student movement demonstrating against the government.⁶¹ While Candela did not write about these events, they clearly affected his position with regard to Mexico and his determination to leave the country.

In addition to the economic and political turmoil in Mexico, Candela’s life also dramatically changed with the loss of his wife in 1963 and his marriage, in 1967, to the architect Dorothy Davies, whom he had first met as a visiting professor at UC Berkeley. This further connected Candela to the US, and although they lived in Mexico City shortly after their marriage, they soon left for New York.⁶² Already by 1965, Candela had embraced the opportunity to work with the New York-based firm Praeger-Kavanagh-Waterbury on proposals for a sports facility at Brown University. In retrospect, Candela recalled: “that’s one of the reasons why I left Mexico. I was already working in New York, and I wanted to see if I could get rid of the economic problems of the company [...] living more freely.”⁶³ This casual sentence from an interview reveals that Candela did not only actively seek opportunities to move to the US, but that the economic problems of Cubiertas Ala were mounting and his departure from the company was well underway by the mid-1960s. While he continued to build numerous projects in Mexico until 1969—most notably three Metro Stations for Mexico City’s Line 1 and, of course, the Palace of Sports for the Olympics—the project for Brown University seemed to appear most promising for Candela.

While the project was ultimately canceled in 1971 after many drafts and revisions, Candela spent much energy on it, knowing that it could manifest his position in the US and result in more building projects there. Even though it never materialized, the stadium for Brown was an important milestone. It arrived on his desk at an ideal time to transition his practice, not just from Mexico to the United States but from small-scale shell construction to large-span domes. The first design was a partial sphere of a metal grid between which hypars were suspended.⁶⁴ Candela’s drawings for the first proposal show his rethinking from self-supporting curvatures in concrete to a composite structural system that integrates hyperbolic paraboloids. This exercise directly influenced the design for Mexico’s Palace of Sports—a project so similar that some of its drawings have frequently been misattributed. The rapid design and drawing process for the Sports Palace was only made possible by the work that already commenced on the project for Brown University; and the building of the Mexico City project would in turn influence subsequent iterations of the project in Providence. Even after it became clear that the project for Brown University would not move ahead, Candela hoped that his association with Praeger-Kavanagh-Waterbury would result in further projects, but the partnership dissolved in 1971. Personal letters reveal how uncertain and precarious Candela’s professional and financial situation was during this time, burdened by outstanding payments from Cubiertas Ala and in disputes with family members who continued to run the firm. In August of 1971, Candela writes in a letter: “My brother Antonio stayed with the business and is doing great, buying new cars and taking trips to Vegas at the slightest opportunity, but he refuses (supported or persuaded by Julia) to give me any of what he owes me. At the New York office it seems they didn’t need my services and I had to retire a couple of months ago.”⁶⁵

It was during this time that his friend and Dean of UICC’s College of Architecture and Art, Leonard Currie, pursued Candela and ultimately offered him a professorship in Chicago. The two had known each other since the 1950s when Currie was director for housing, planning, and community development for the Inter-American Housing Center in Bogotá, Colombia and they had become friends soon after. In 1964, Currie was responsible for the meeting between Netsch and Candela, and he might even have joined their stroll across UICC’s campus, possibly showing Candela the site of his new architecture school. The building would be inaugurated in 1967 and four years later would become Candela’s new academic home. In what appears to be a well-staged prelude to bring Candela permanently to Chicago, Currie organized the “Graham Seminars” in Spring of 1971, a three-day lecture and seminar marathon at UICC, IIT, and the Education Committee of the Chicago Chapter of the American Institute of Architects (AIA). In his request for funding to John Entenza, director of the Graham Foundation, Currie already describes Candela as a potential “visiting professor and consultant” in Chicago because of Candela’s new proximity to the city, since he had recently moved “his principle base of operations from Mexico City to New York.”⁶⁶ This was surely a prospect that appealed to Entenza, who was familiar with Candela since his time as editor of the California-based Arts & Architecture Magazine, which had published Candela’s work and his High Life Textile Factory appeared on the cover of the May 1956 issue. Sponsored by the Foundation, Candela’s trip on April 21-23, was densely packed to showcase his expertise on thin-shell concrete construction to constituencies related to architectural education. Spending one day on each campus, Candela’s daily schedule entailed a public lecture, a seminar and studio critiques with faculty and students, and a luncheon “with a small group of administrators and faculty.”⁶⁷ On the third day, Candela toured “the most important new buildings in Chicago” as well as “some of the larger Chicago architectural offices.”⁶⁸ In addition, he met with the AIA to plan a continuing education course in concrete design and technology for the coming fall. These arrangements were not only intended to introduce Candela to the Chicago architectural community, but they also set plans in motion that facilitated his continued involvement beyond the seminars.

The first day at UICC concluded with a “Sangría-Fiesta with Candela,” a large party at the house of the Curries, who lived just west of campus. Candela had brought his wife on this three-day trip, which for them was also an occasion to familiarize themselves with the city and, possibly, to gauge if they could live there. The different events across the city, the meetings that gathered educators and architects, and the parties that followed all point to a staged presentation of the Candelas to Chicago, and vice versa advertising UICC to the Candelas. In his communication to arrange the events, Currie described Candela’s visit as a unique opportunity to bring “his remarkable talents to Chicago,” as someone who would “provide insights and stimulation to […] local architects and structural engineers,” and who is “willing to so arrange his busy schedule to permit a three-day visit.”⁶⁹ Clearly, Currie was planning more than just an additional lecture during the Spring semester. To Chicago, he portrayed Candela’s visit and potential return as an exceptional chance that could inspire and motivate the discipline; while to Candela, he portrayed Chicago as an opening for a new chapter and—as the AIA workshop signaled—a willing territory for collaborative explorations in concrete.

Whether Currie knew it or not, for Candela, the offer to join UICC in Fall of 1971 could not have come at a more opportune time. Numerous letters by Candela describe Currie as “a good friend of many years and an excellent person who has bailed me out at a very difficult time in my life.”⁷⁰ While UICC was not one of the prestigious private universities that previously had invited Candela as a visiting professor, we understand from his many letters to friends and colleagues that Chicago appealed to him as a city where he would also “have opportunities to do something outside of class.”⁷¹ No doubt swayed by the exhaustive introductions to Chicago’s architecture scene and the hospitable welcome of institutions orchestrated by Currie, UICC likely appealed more than most other places that Candela was associated with. At Cornell University in the secluded town of Ithaca, for example, Candela had held the Andrew D. White Professor-at-large post from 1969 to 1974. From his earliest engagements with Chicago through exhibitions in the late 1950s and early 1960s to his visit in 1964 and his celebrated and triumphant Graham-Seminars in spring of 1971, Candela’s view of Chicago was understandably one of potential and promise, not foreseeing all the difficulties that his kind of architectural practice would face in the city.

For the full version of this essay, please see “Departures and Arrivals,” in Félix Candela from Mexico City to Chicago, ed. Alexander Eisenschmidt (Barcelona: Actar, 2024), 158–183.