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Performative perforations: structural and daylighting performance assessment of Candela's High Life Textile Factory

Abstract and Figures

Felix Candela designed and built one of the simplest and most practical shells: umbrella shells. Among his built umbrellas, only a few are perforated, including the High Life Textile Factory. This Factory consists of aggregated umbrella shells with distributed perforations. Although the shells are tilted towards north to create a saw-tooth cross section that brings reflected light into the space, the perforations also played a role in providing daylight. After the building was used as an iron shop, the perforations were covered with asphalt to reduce overheating of the space caused by the hot Mexican climate and the program of the factory. However, it was never studied if covering the perforations would truly have been effective in mediating the overheating. This research speculates Candela's motivations in perforating the shells. It first examines where this building falls in his career and if he continued designing other perforated shells. Next, the building is simulated to assess its structural, daylighting, and energy performance, with and without the perforations. The goal is to understand the role of perforations on performance, and if covering them has helped to decrease the cooling load. The result of this study reveals design potentials of Candela's less-talked-about project, the High Life Textile Factory, to better understand his motivation in perforating the shells: Were Candela's perforations performative?
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Proceedings of the IASS Symposium 2018
Creativity in Structural Design
July 16-20, 2018, MIT, Boston, USA
Caitlin Mueller, Sigrid Adriaenssens (eds.)
Copyright © 2018 by <Niloufar EMAMI, Harry GILES, Peter VON BUELOW>
Published by the International Association for Shell and Spatial Structures (IASS) with permission.
Performative perforations: structural and daylighting
performance assessment of Candela’s High Life Textile Factory
Niloufar EMAMI*, Harry GILESa, Peter VON BUELOWa
* a b University of Michigan
Taubman College of Architecture and Urban Planning, 2000 Bonisteel Blvd. Ann Arbor, MI
nemami@umich.edu
Abstract
Felix Candela designed and built one of the simplest and most practical shells: umbrella shells. Among
his built umbrellas, only a few are perforated, including the High Life Textile Factory. This Factory
consists of aggregated umbrella shells with distributed perforations. Although the shells are tilted
towards north to create a saw-tooth cross section that brings reflected light into the space, the
perforations also played a role in providing daylight. After the building was used as an iron shop, the
perforations were covered with asphalt to reduce overheating of the space caused by the hot Mexican
climate and the program of the factory. However, it was never studied if glare might have been another
reason for covering the perforations, and if covering the perforations would truly have been effective in
mediating the overheating. This research speculates Candela’s motivations in perforating the shells. It
first examines where this building falls in his career and if he continued designing other perforated shells.
Next, the building is simulated to assess its structural, daylighting, and energy performance, with and
without the perforations. The goal is to understand the role of perforations on performance, and if
covering them has helped to decrease the cooling load. The result of this study reveals design potentials
of Candela’s less-talked-about project, the High Life Textile Factory, to better understand his motivation
in perforating the shells: Were Candela’s perforations performative?
Keywords: perforated shells, concrete shells, parametric design, performance-based design, interdisciplinary design, structural
performance, daylighting performance, energy performance
1. Introduction
Felix Candela (1910-1997) was a Spanish-born master builder and structural engineer. He enrolled at
the Central University of Madrid where he took two demanding years of mathematics and physics before
qualifying for enrolment in architecture or engineering. Eduardo Torroja had designed the mathematics
curriculum of this program (Cassinello and Torroja [1]). After Candela finished his studies in 1935, he
got involved in the Spanish Civil War and ultimately was exiled to Mexico in 1939. Therefore, many of
his structures were built in Mexico.
Candela used hyparbolic paraboloids in the design of his shells and described them as the “easiest and
most practical to build” (Garlock and Billington [2]). The shape is also referred to as hypar and has the
property of being defined by straight lines. The edges of the hypar can be straight or curved. He used
the hypar with straight edges in many structures. According to Garlock and Billington (2008: 98)
“Candela’s bread-and-butter structure was umbrella, a hypar with straight edges all in the same plane.”
In fact, he had roofed 3,000,000 sq. feet in the new industrial zones of Mexico City with umbrellas, in
shapes of “square or rectangular, rhomboidal, polygonal” in “churches, warehouses, factories, hotels
and restaurants, residences, in a bank and even in a casino” (Faber [3]). A straight-edge hypar consists
of four areas (Figure 1-left). One area is then retrieved from the hypar to create an umbrella structure
(Figure 1-right). In many design projects, Candela placed multiple umbrellas in sequence to create large
roof coverings. Candela introduced daylight to the spaces that were covered with multiple umbrellas
Proceedings of the IASS Symposium 2018
Creativity in Structural Design
2
either by tilting the umbrellas to create a sawtooth roof, or by varying the height of umbrellas in each
row, or even by piercing the shell with glass blocks [2].
Figure 1: Straight edge hypar (left); umbrella shell (right)
Considering the design strategies that Candela employed to bring daylight into the space, his perforated
aggregated umbrella shells are chosen to be examined from a multidisciplinary design lens. The High
Life Textile Factory is one of the few perforated shells that he built, which is an example of a roof
typology integrating form, structural performance, and environmental design. The umbrella shell is
modeled in Rhino and Grasshopper to assess its structural, daylight, and energy performance. The
Karamba plugin is used for structural evaluation, while the DIVA and Archsim plugins are used for
daylighting and energy assessment respectively. Deflection and von Mises Stress are measured using
the former, while Spatial Daylight Autonomy (sDA), point-in-time glare, and energy loads are measured
for the latter. The daylighting and energy simulations are repeated for the aggregated shells with
perforations only, and then for aggregated shells with side lights only. The goal is to understand the
effect of adding perforations on the daylighting and energy, and to answer: were Candela’s perforations
performative? or were they a sculptural art work from a structural artist? And why did Candela rarely
repeated building perforated shells later in his career?
2. Where does High Life Textile Factory fall in Candela’s career?
Candela’s first umbrella was built in 1952 and measured 10 by 10 meters (33 by 33 feet) with a rise of
1 meter (3 foot 4 inches) and a thickness of 4 centimeters (1½ inch). His second experimental umbrella
was built in 1953 and measured 8 by 8 meters (25 by 25 feet), with a rise of 0.75 meters (2 foot 4 inches),
and a thickness of 8 cm (3¼ inch). This second umbrella was subject to higher live load, and despite
the increased thickness and heavy reinforcement, the corner deflection was several centimeters under its
own weight after a few weeks. Several men standing on the umbrella did not increase the deflections, so
Candela assumed that the deflections were due to insufficient rise of the umbrella (Garlock and
Billington =98). After building these two experimental umbrellas, the Rio’s Warehouse was built in
1954. It consisted of solid umbrellas measuring 10 by 15 meters (32 by 49 feet) with a 2-meter rise (6½
foot). Rio’s Warehouse “initiated the umbrella shell as Candela’s trademark for low-cost industrial
construction” (Garlock and Billington =102). Candela later mentioned that the optimum rise depends on
the area covered by the umbrella, and his formula was that the rise equaled 0.015 times the area. He also
noted that umbrellas have a coverage size limitation of 185 square meter (2000 square feet), and
deflections will be difficult to control if the area and the rise of the umbrella increases.
The High Life Textile Factory was built in 1954-55 in the Coyocan section of the Mexico City and after
Rio’s Warehouse. 44-year old Candela designed and built his first perforated umbrella shell which also
presents a saw-tooth profile. The square-shaped perforations in this shell are rotated 45 degrees in the
direction of straight-line generators. To understand the reason behind the rotation of the perforations,
reinforcement placement in the shell needs to be examined. Candela analyzed the umbrella shells using
the membrane theory, and he noticed that the direction of tension and compression forces along the
umbrella structure is acting 45 degrees in the direction of the straight-line generators (Figure 2-left). He
then placed steel reinforcement in a matching layout, which can be seen in a picture from the
construction of one of his umbrella shells (Figure 2-middle). The practical placing of the reinforcement
distribution in the shell explains 45 degrees rotation of square perforations so they fit in the grid created
between the intersecting reinforcements (Figure 2-right).
Proceedings of the IASS Symposium 2018
Creativity in Structural Design
3
Figure 2: The straight line generators (left); steel reinforcement in Candela’s typical shells (middle); 45° rotation
of openings from edge in the High Life Textile Factory (right) [2]
There is another important structural design element in the tilted umbrellas, examined in both Rio’s
Warehouse and the High Life Textile Factory (Figure 3). The vertical struts play a crucial role in
maintaining stability of the entire roof system. As Faber (1963:111) explains, tilted umbrellas “were
grouped horizontally and isolated by flat ribbons of light. Every three feet or so, slender struts connect
their edges, adding rigidity to the shells, guarding against sway.” Each pavilion is a huge cantilever
which is self-supporting under symmetric loading, but very unstable under local patterned loading that
would cause instability back to the supporting perimeter walls.
Figure 3: cross section of tilted umbrellas connected by vertical struts (left); vertical struts seen in the Rio’s
Warehouse (middle); vertical structs in High Life Textile Factory (right)
A summary of the dimensions of the experimental umbrella shells as well as Rio’s Warehouse and High
Life Textile Factory are summarized in Table 1. The Rise/Area ratio is calculated for each case to be
compared to Candela’s suggested ratio of 0.015.
Table 1: comparing dimensions and thickness of the first umbrellas built by Candela
Length
[m]
Width
[m]
Area [m^2]
(limit 185)
Rise
[m]
Thickness
[cm]
First experimental umbrella (1952)
10
10
100
1
4
Second experimental umbrella (1953)
8
8
64
0.75
8
Rio’s Warehouse (1954)
10
15
150
2
4
High Life Textile Factory (1954-55) i
12
12
144
2
4
Once the High Life Textile Factory shell was built, glass blocks were installed in the perforations, and
the factory was used as a sewing and ironing shop. After building was in use, the glass bricks were
covered with heavy asphalt paper and tar. Garlock and Billington (2008:2012) explain that it was due to
overheating problems: “the factory was used as a sewing and ironing shop, where women ironed all day
with steam. Combined with the hot Mexican sun, the heat inside the shop was more than anyone could
bear. In the end, it was necessary to cover the glass bricks with heavy asphalt paper and tar.” Colin Faber
(1963: 111) admires the daylighting quality of the space covered by perforated shell but considers glass
bricks as one of the reasons for overheating problems. He states, at frequent measured spots, the roofs
are pierced by glass bricks. Light floods the factory, as if there were no roof at all. But the brilliant
mosaic provoked such heat and insulation problems that it was never repeated.” The use of glass block
in this manner was not repeated by Candela, although he used tilted umbrellas to allow light to enter the
structure in other projects (Garlock and Billington [2]). In fact, Candela only built one other perforated
umbrella shell. Later in 1958, he worked in collaboration with the American engineer O’Neil Ford to
erect a series of hypar structures for the Insignia of the Great Southwest Corporation in Forth Worth,
Texas (Mendoza [4]). These shells are perforated too, however, the perforations are fewer than the High
Proceedings of the IASS Symposium 2018
Creativity in Structural Design
4
Life Textile Factory, and the purpose seems to be for aesthetics rather than for introducing daylight, as
they are built in an open space.
Figure 4: interior image of the iron shop (left); Insignia of the Great Southwest Corporation, Texas (right) [4]
3. Geometric properties and methodology
The dimensions of the factory were not found in the literature. However, it was measured using google
maps (Decimal Degrees = 19.354074, -99.162826). The width and length of one umbrella is measured
12 by 12 meter. Looking at the site plan, an array of 4 by 3 umbrellas is recognized (Figure 5-left).
Looking at the perspective view, the saw-tooth roof is recognized facing North (Figure 5-middle). The
plan view of the High Life Textile Factory is reproduced using the measured dimensions of a unit
umbrella, suggesting that the building measures 48 by 36 meters (Figure 5-right). Having not visited the
site nor finding the dimensions in the literature, the rise and thickness of the High Life Textile Factory
is assumed to be the same as Rio’s Warehouse (the aggregated umbrella shells that were built right prior
to this project). Therefore, the rise is assumed to be 2 meters and thickness is set to 4 cm. Since the
perforations are currently covered, the dimensions of the square perforations could not be measured on
Google maps, therefore, based on the available images, they are assumed to have a length of 10 cm.
Figure 5: Plan view of the aggregated shells (left); tilted shells towards North (middle); reproduced plan (left)
Figure 6: Recreated perforated shells using Rhino and Grasshopper
Once the shells are computationally modeled in Rhino and Grasshopper, the structural performance of
the shells as well as the daylighting and energy performance of the space is simulated. Karamba plugin
for Grasshopper is used for structural analysis, while DIVA and Archsim plugins for Grasshopper are
used for daylighting and energy analysis respectively. Each simulation setup and the results are
explained in the following sections.
4. Structural simulation setup and results
Karamba plugin is a Finite Element Method simulation engine in Grasshopper. The umbrella shells are
supported on the valleys, and their movement and rotation are restricted in x, y, and z direction (Figure
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Creativity in Structural Design
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7). In addition, there are vertical structural elements between each row of umbrellas connecting the tilted
umbrellas to the adjacent row. These are modeled as monolithic pieces to the whole system. A distributed
symmetrical global load is applied to the shell and self-weight is included in the simulation. The
thickness of the shell is set to 4 cm, and concrete is used as the material. The material properties and
load values are summarized in Table 2.
Figure 7: Boundary conditions for structural analysis
Table 2: material properties for structural simulation
Load 1_
distributed
[KPa]
Load 2 [KPa]
E (Elastic
Modulus)
[MPa]
G (Shear
Modulus)
[MPa]
Fy (yield
strength)
[MPa]
Density
[Kg/m^3]
Specific
Weight
[KN/m^3]
-1
Gravity
26,000
10,800
30
2400
23.5
The simulation results are presented in Table 3, and simulation images are presented in Figure 8. The
total deflection is 1.1 cm, which is within the limits (span/300 = 1200/300=4). The edges of the umbrella
are going through maximum deflection as seen in the simulation image (Figure 8-left). The maximum
von Mises stress is seen in the umbrella valleys (Figure 8-middle). Looking at the principle force flows
where blue represents compression and red represents tension, it’s also suggesting that the umbrella
edges are going through tension and need additional steel reinforcement, as Candela did in his designs.
Table 3: structural simulation results for 4-cm umbrella shells
Mass [kg]
Weight
[tonne]
Deflection
under D.L.
[cm]
Deflection
under L.L.
[cm]
Total
deflection
[cm]
Von Mises at
Q3 [MPa]
Maximum
Von Mises
[MPa]
268,141
268
0.99
1.1
2.1
1.41
8.76
Figure 8: maximum deflection in the whole roof(left); von Mises Stress (middle); principle stress lines (right)
5. Daylighting simulation results
The surface properties of the walls used in the daylighting simulation are summarized in Table 4,
affecting the daylighting performance of the space when Mexico City is set as the location.
Table 4: surface properties for daylighting simulation
Location
Measurement
plane
Floor
material
Interior wall
material
Roof
material
Glazing
material
Outside
ground
material
Mexico City
0.9 meter
above ground
Generic floor
(20)
Outside
façade (35)
Generic
ceiling (80)
Single pane
glazing (88)
Outside
ground (20)
Proceedings of the IASS Symposium 2018
Creativity in Structural Design
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The daylighting simulation is computed for three scenarios: first, original umbrella shells designed by
Candela having both perforations and north lighting; second, a hypothetical condition for umbrella shells
having perforations only; and third, the current condition of the factory where the perforations are
covered with asphalt and north light is the only source of daylight. The Spatial Daylight Autonomy
(sDA) in the first scenario is simulated to be 85%, meaning that the daylight alone would have been
sufficient to meet the daylighting needs of the space, (300 lux on the horizontal plane). The second
scenario with perforations only has a sDA of 40%, which is not considered a daylit space, but is partially
providing daylight. The third scenario has a sDA of zero, implying that the building is highly dependent
on electrical lighting for illumination. The point-in-time glare at noon on June 21st is computed for all
three scenarios and is “imperceptible glarein all. Based on the daylighting simulations, covering the
perforations in Candela’s original shell has significantly reduced the daylight availability in the space.
The comparison of the daylighting simulation result is summarized in Table 5.
Table 5: Visualization and performance values for different design scenarios of umbrella shells
Scenario 01: Original
Umbrella, perforations +
north light
Scenario 02: Hypothetical
Umbrella, perforations
only
Scenario 03: Current
Umbrella, north light
only
Plan view of Daylight
Autonomy
sDA (%Area>50%,
DA=300 lx)
85%
40%
2.6%
DAv oversupply
32%
29%
0
Fish eye view of the
interior space
Glare (06/21 at noon)
Imperceptible glare
Imperceptible glare
Imperceptible glare
6. Energy simulation results
The area of the space is calculated as 1720 m2 (36 m* 48 m). The area of the perforations and the north
light panels is calculated as 121.2 m2, and 121.9 m2 respectively. For internal heat gain, the factory is
assumed to have equipment heat gain of 46 W/ m2
ii
, artificial lighting heat gain of 10.4 W/ m2
iii
and an
occupancy of 0.1 person/ m2
iv
. The factory is assumed to be fully occupied on weekdays between 8 a.m.
and 6 p.m.
Table 6: settings for the energy simulation
Walls and
roof
Ground
Glazing
Zoning
Equipment
power
density
Lighting
power
density
Occupancy
load
Occupancy
Schedule
15 cm
concrete-
Adiabatic
Single
pane
clear
Factory
considered
as one zone
46 Watt/
m2
10.4 Watt/
m2
0.1 people
per m2
8 a.m. to 6
p.m.
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Creativity in Structural Design
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Looking at the simulation results for the energy consumption of the shop in Mexico City (Figure 9-left),
cooling loads are significantly high compared to the heating and lighting loads. This trend is consistent
in all design scenarios. From a different perspective, the cooling loads have small variation in different
scenarios. In fact, the cooling load of the current umbrella (scenario 3 with north light only) is only
10,000 KW/hr less than the original design (scenario 1 with both north light and perforations). The
simulation results imply that covering the perforations has had minor effect on reducing the cooling load
of the factory and mitigating its overheating problem. It can be concluded that the high internal heat gain
loads caused by irons is not effectively addresses by reducing the sources of natural daylight.
The energy simulations are repeated using a different climate: Boston. The goal is to see the effect of
context on cooling loads, and how the performance of the factory would have been improved if it was
built in a heating dominated climate as opposed to a cooling dominated. Looking at the results (Figure
9-right), when Boston is set as the location, the pattern of cooling loads being considerately higher than
lighting loads is observed again, while heating loads also increase.
Figure 9: Heating, cooling, and lighting load of different design scenarios in Mexico City (left); and Boston (right)
From a different perspective, by changing the context from Mexico City to Boston, the cooling loads in
each design scenario drop by 5.7e5 KW/hr on average. In other words, if Candela could have built the
factory in Boston having the same program, cooling loads would have been about half (Figure 10).
Figure 10: Comparing Cooling Energy for the same program in two different contexts
5. Conclusion
This research employs computational design and simulation tools to recreate one of the less-talked-about
perforated umbrella shells designed by Candela: High Life Textile Factory. This shell covered a sewing
and ironing shop in Mexico City, and its perforations were covered with asphalt and tar after the building
was used. Candela never repeated building a perforated shell in this manner.
One of the goals of this study is to understand the effect of perforations in the structural performance of
Candela’s shells. Being built after two experimental shells and then Rio’s Warehouse, we believe
Candela added perforations to this shell for structural speculations. He might have tried to lighten it, and
also see if he would have needed to increase the thickness upon adding perforations. In other words, it
has been his first experimental perforated shell. The perforations reduce the deadload, and the rational
for placement and rotation of the square perforations relates to the design of underlying reinforcement
layout. Perhaps using circular openings would have been structurally more effective. The effect of
perforations’ size on the structural performance is an interesting subject for further speculations.
Proceedings of the IASS Symposium 2018
Creativity in Structural Design
8
Another goal of this research is to understand if the perforations were performative in the daylighting
discipline, and if they were designed for increased daylighting performance or if it was purely structural
art. The daylighting simulations revealed that the contribution of perforations towards providing daylight
is quite significant, as the current situation with north-light only does not meet the daylighting
requirements of the space. The perforations were playing a role in bringing adequate daylighting into
the space, and by covering them, the daylighting performance has significantly declined. Regarding
glare, although the point-in-time glare simulation shows imperceptible” glare, the patterning of the light
might have been problematic for factory workers upon working with the machinery. In case of existence
of glare or patterning, internal blinds could have been used to bounce the light back onto the underside
surface of the shell and better diffuse the light. Candela’s perforations were performative in the
daylighting discipline, and the decision to cover the skylights is a lost opportunity of good daylighting.
Another goal of this research is to speculate if perforations have been one of the reasons of overheating
of the space as stated in the literature, and if yes, then how covering them has mitigated the problem.
The energy simulation results for the shells with and without the perforations
v
, suggests that there is
insignificant reduction in cooling loads in the shells without the perforations. In fact, the heat gain from
the irons from inside the building is the driving force in overheating the space. The role of hot Mexican
climate on the overheating of the space is also studied by repeating simulations using a different climate
from Mexico City (Boston here). The results reveal that the cooling loads would have been half in a
heating-dominated climate such as Boston, as compared to its original climate, Mexico City. We believe
it was unfortunate that the program of the factory created the overheating problem and perhaps the
owners of the shop covered the perforations in the first step assuming that it will mitigate the overheating
problems caused by the irons. The energy analysis shows insignificant change in cooling loads before
and after covering the perforations.
Future research that builds on this study is focused in two areas. First, to get more accurate information
on the building and site, by going to archives to find the accurate dimensions of the shell and visiting
the site to see how the perforations are covered, and if the accurate dimension of the perforations can be
retrieved. This might also lead to answering questions regarding if the factory is still functioning the
same. Second, to understand why Candela did not repeat building a perforated shell for another space?
The only other perforated shell that he has built belongs to the Insignia of the Great Southwest
Corporation in Forth Worth, Texas, which is a free standing sculptural shell. Maybe the disappointment
from covering the perforations prevented him? Maybe there were some leaking problems at the
connection of glass blocks and concrete due to nonexistence advanced synthetic sealants? Or maybe the
costs of making the performed shells were too high at the time, and so he decided not to repeat it?
References
[1] P. Cassinello and J. A. Torroja, “Félix Candela: His vocational training at the university and his subsequent
relationship with the institute founded by Eduardo Torroja,” J. Int. Assoc. Shell Spat. Struct., vol. 51, no.
163, pp. 8795, 2010.
[2] M. M. Garlock and D. P. Billington, Felix Candela, Engineer, Builder, Structural Artist. Yale University
Press, 2008.
[3] C. Faber, Candela , the shell builder . With a foreword by Ove Arup. 1963.
[4] M. Mendoza, “Felix Candela’s first European Project : The John Lewis Warehouse , Stevenage,” Arq
Archit. Res. Q., vol. 19, no. 2, pp. 149160, 2015.
i
The length and the width are measured from Google Maps, while the rise and the thickness are assumed to be
similar to Rio’s Warehouse.
ii
40 irons each consuming 2000 Watts/hr, divided by the 172 m^2 floor area.
iii
2.5-meter fluorescent lamps with 2 lamps are assumed to be used. It is assumed that 19 lamps are used in a row
to lighten 48-meter width of the space, which is then repeated in 6 rows. A total of 114 fluorescent lamps are used
each consuming 158 Watts/hr, totaling to 18012 Watt/hr. This number is divided by the floor area (172 m^2) to
arrive at 10.4 Watt/m^2 lighting heat load.
iv
This assumes that 172 workers were working in the factory
v
Single pane glazing is used for energy simulations as opposed to glass bricks.
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Article
Félix Candela holds a prominent position in the chapter of modern architecture on thin concrete shells. While most of his legacy is to be found in Mexico, where he lived in exile for much of his adult life, his interest in shell design and his sound university training were acquired in Madrid. Candela studied at the city's Faculty of Science (1927-1929) and its School of Architecture (1929-1935). The university's mathematics curriculum was designed by Eduardo Torroja Caballé, who had revolutionized mathematics analysis teaching in Spain. In 1935, his son, Eduardo Torroja Miret, built two of his famous thin shells in Madrid: the Zarzuela Race Track and the Recoletos Jai-Alai Court. Although Félix Candela was not to return to Madrid until 1969, he never ceased to admire Eduardo Torroja and the institute founded by that eminent engineer. That admiration nourished a close relationship with both from the nineteen fifties onward, when Candela's Mexican company, "Cubiertas Ala" (1950), began to build its acclaimed reinforced concrete shells. Candela collaborated for many years with the IASS, an association founded at the Institute under Eduardo Torroja's leadership in 1959.
Article
Felix Candela’s hyperbolic paraboloid reinforced concrete structures - also known as hypars - were not only masterly used in his well-known religious buildings but they were also ingeniously and profusely employed to roof a vast number of industrial buildings during the Mexican industrialisation era. Candela’s inverted hypar shells prototype for industrial buildings became a trademark for a systematic and standardised construction method which crossed the Mexican borders to reach and influence the work of other architects and engineers further afield. In the United Kingdom this is exemplified by the John Lewis Warehouse (JLW) at Stevenage in which Candela worked as co-designer and consultant of the post-War architectural firm Yorke, Rosenberg and Mardall (YRM) and the engineers Clarke Nicholls and Marcel. The JLW represents a unique structure in the repertoire of Candela’s work outside Mexico for two main reasons. Firstly, it stands as Candela’s first European project and secondly it represents a structure in which ‘automatic beauty’ was achieved through economic efficiency and the use of more sophisticated construction methods than those conventionally used in Mexico. Moreover, and beyond its structural and constructional merits the JLW yields a spatial richness which transformed the ephemeral of the working day to forge spaces of mnemonic identification. Built in 1963, the JLW is an epitome of structural art amongst the industrial buildings of Britain's post-Austerity period. Candela’s first European project is analysed not only in terms of its structural and constructional merits but also in relation to its spatial poetics.
Candela , the shell builder . With a foreword by Ove Arup
  • C Faber
C. Faber, Candela, the shell builder. With a foreword by Ove Arup. 1963.