BETWEEN THE TECTONICS OF LOAD-BEARING AND THE TECTONICS OF DRESSING1 In the context of architecture’s renewed interest in brick as a building material the term brick tectonics has surfaced as one, with which the material’s proper use seems to be indicated. The term’s frequent use suggests that its meaning is well defined. However at closer inspection, one finds that it is not readily clear what brick tectonics precisely means. This essay is an attempt to engage in a fundamental investigation of what the meaning of brick tectonics could be. To begin with the terms brick architecture and tectonics will be separately reconsidered. Following the theories of Karl Bötticher and Gottfried Semper I will propose to distinguish at least two kinds of tectonics. The subtitle of this essay accordingly refers to them as the tectonics of load-bearing and the tectonics of dressing. Herewith the term tectonics, which usually is associated with load-bearing, is expanded and differentiated. Arising from this one can also distinguish in brick architecture two types of tectonics offering two distinct design approaches for the contemporary architect. An intermezzo will deal with the relatively recent phenomenon of the expansion joint. It arguably constitutes the biggest challenge to both types of brick tectonics. In the conclusion the influential position of the German architect Hans Kollhoff, who also has a considerable practice in the Nether-lands, will be addressed. Hans Kollhoff ’s particular position on the tectonics of load-bearing incorporates an important principle of the tectonics of dressing: the principle of masking. It affords his architecture to draw on the classical tradition while being built with contemporary construction techniques.

BRICK ARCHITECTURE In a dictionary of building terminology, brick architecture is defined as ‘architecture that uses brick structurally, as a stacking material of small dimensions. The brick performs a load-bearing function, and therefore is not

Udo Garritzmann

1 I wish to thank Jan Peter Wingender and the Brick Tectonics research group for the stimulating debate and suggestions that have greatly contributed to this essay. Also I would like to thank architect Joris Molenaar; and Dirk Jan de Vries, professor in the history of building, for the kind exchange of thoughts and knowledge on brick outside the confines of this research group.

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of material on form-making, he also considers the tools and procedures that were applied to the material in the process of form-making. With this difference in mind, I will discuss Bötticher and Semper as representatives of two distinct tectonic positions: the tectonics of load-bearing and the tectonics of dressing.

BÖTTICHER: THE TECTONICS OF LOAD-BEARING The architect Karl Friedrich Schinkel was an important inspiration behind Bötticher’s 1852 magnum opus Die Tektonik der Hellenen.6 It was Schinkel’s design of the Altes Museum that had triggered Bötticher’s interest in the aes-thetic principles of Greek antiquity in the first place. And it had been at Schin-kel’s instigation that Bötticher was teaching the courses free-hand drawing and ornament drafting at the Bauakademie in Berlin. Since Schinkel’s Architek-tonisches Lehrbuch remained unfinished and the notes for it unpublished, the students of the Bauakademie used Die Tektonik instead, and as such saw it as the missing theory behind Schinkel’s architecture. Bötticher viewed Schinkel’s architecture as one of the sparse contemporary examples in which the essence of ancient Greek Architecture had survived. Die Tektonik der Hellenen was an effort to explicate the principles of classical Greek architecture. Bötticher proposed the complementary terms core form (Kernform) and art form (Kunstform) to conceptualize the appear-ance of a building in relation to the structural forces at work in its physical building parts. While the former corresponds to the structurally necessary parts of a building, it is the latter that makes the structural workings of the core form actually perceptible and intelligible. Here, art form can be seen as a synonym for proper adornment (or ornament). Bötticher considers an orna-ment proper if it expresses the structural forces of the core form in it’s deco-ration. Both core form and art form are mutually dependent; it is inconceivable for Bötticher that one could exist without the other. Bötticher categorizes art forms according to the structural performance that they articulate. He distinguishes the following in Greek architecture: symbols for the crest, symbols for load-bearing and supporting in conflict (cyma), symbols for free-standing stem- and stipe-like columns, symbols for belts, symbols for conjunctions of whole structural parts (abacus), symbols for parts floating above space and free-floating parts (geison). Each building element takes a precise position in the building’s larger whole, which is conceived as a complete system of all constituent parts. Archi-tecture is beautiful when it expresses the structural workings of its building components in its ornamentation. Bötticher thought of this as a timeless

just filling or dressing’. The dictionary entry concludes that ‘the application of reinforced concrete makes it possible to let whole brick masses not fulfil a load-bearing function, but to suspend them from the load-bearing structure or use them only as filling material. Here one cannot talk about brick archi-tecture in the strict sense of the word’.2 It is probably clear that few buildings in the Netherlands that appear to be built in brick today would actually meet the qualification of brick architecture as stated in the quote above. ‘Recent’ brick architecture usually refers to build-ings that use brick precisely as dressing or filling. It should not come as a surprise then that this dictionary focuses pri-marily on architecture from pre-1900, and that its authors were or still are involved in the preservation and restoration of Dutch architectural heritage. The entry is interesting nonetheless, because its two opposing criteria — load-bearing and dressing — were also two key terms in the discussion of tectonics in German architectural theory in the mid-19th century.3

TECTONICS: KARL BÖTTICHER VERSUS GOTTFRIED SEMPER Before reflecting on the meaning of tectonics in contemporary brick architecture, I will recapitulate the meaning of tectonics itself. I will do this by way of the theories of Karl Bötticher and Gottfried Semper.4 These authors were the most important protagonists in the original tectonics debate. Semper launched a heated polemic against Bötticher when he discovered that Bötticher had anticipated his ‘principle of dressing’ with his concept of ‘art form’. Wolf-gang Hermann has carefully investigated the conceptual similarities and dif-ferences between Bötticher and Semper’s thinking.5 Both authors had similar views on Hellenic architecture. Even Semper’s use of the term tectonics seems to be indebted to Bötticher. Essential to my argument here, however, is a difference between Böt-ticher and Semper that Hermann points out. It concerns the relevance that is attributed to material as a formative factor, which is of decisive importance for Semper but not for Bötticher. When Semper conceptualizes the influence

The Tectonics of Brick Architecture

2 Haslinghuis, Janse, Bouwkundige Termen, Verklarend Woordenboek van de Westerse Architectuur- en Bouwhistorie, Leiden 2005, 5th edition, pp. 47–49, (1997, 1st edition), translation by the author.

3 Combining these aspects of tectonics with our initial definition of brick architecture would either lead to a tautology (the tectonics of brick architecture = load-bearing + load-bearing brick) or to a contra-diction (the tectonics of brick architecture = non-load-bearing dressing + load-bearing brick).

4 As a general introduction to both Bötticher and Semper see: Oechslin, Werner, Stilhülse und Kern, Zürich / Berlin 1994. As an introduction to Bötticher: Mayer, Hartmut, Die Tektonik der Hellenen, Stutt-gart / London 2004. As an introduction to Semper: Mallgrave, Harry Francis, Gottfried Semper, New Haven / London 1996.

5 Hermann, Wolfgang, Gottfried Semper: In Search of Architecture, Mass. 1998, pp. 139–152. Chapter Semper and the Archaeologist Bötticher. 6 Bötticher, Karl, Die Tektonik der Hellenen, 2 volumes, Potsdam 1844–1852, atlas.

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principle and normative rule. This aesthetic idealism derived from the struc-tural forces resulted in a decoration that could be rationally defended. In the 19th century, this position went against the current of decorative practice that favoured the arbitrary choice of eclectic styles on the basis of subjective taste.

SEMPER: THE TECTONICS OF DRESSING Gottfried Semper was concerned about the unbridled proliferation of decoration and ornament in the 19th century as well. But instead of choosing sides in the ongoing style debate, Semper’s 1863 magnum opus Style in the Technical and Tectonic Arts; or, Practical Aesthetics aims to reveal the formal principles inherent in any style by concentrating on the material and technical preconditions of form.

THE FOUR ELEMENTS OF ARCHITECTURE In 1851, roughly a decade before the publication of Style, Semper had proposed in his essay The Four Elements of Architecture a general theory of architecture in the form of a new version of the primordial hut. The four elements

referred to in the essay’s title are: the hearth, the mound, the roof and the enclo-sure. The hearth, or fireplace, is considered the first and most important ele-ment that had to be protected from the ‘hostile elements of nature’ by the three other elements of architecture.7 Each of the four elements of architecture could be related to one of the applied arts. Semper thoroughly scrutinized this idea in Style. The hearth is associated with ceramics; the mound is related to stonecutting (stereotomic); the roof is attributed to tectonics (carpentry); and the enclosure is related to the textile arts. Semper asserts that in the applied arts the formal motives had come into being long before architecture had become monumental, and that architecture had received its entire formal repertoire from the vocabulary of the applied arts. The textile arts, which were preceded by wickerwork, played a central role in Semper’s argument. It is epitomized in ‘the principle of dressing’, which perhaps is the best-known passage in Style. The following passage from The Four Elements of Architecture already contains its main thoughts:

Wickerwork, the original space divider, retained the full importance of its meaning, actually or ideally, when later the light mat walls were transformed into clay, tile, brick, or stone walls. Wickerwork was the essence of the wall. Hanging carpets remained the true walls, the visible boundaries of space. The often solid walls behind them were necessary for reasons that had nothing to do with the creation of space; they were needed for security, for supporting a load, for their permanence, and so on. [… ] Even where building solid walls became necessary, the latter were only the inner, invisible structure hidden behind the true and legitimate representatives of the wall, the colourful woven fabric. The wall retained this meaning when materials other than the original were used, either for reason of greater durability, better preservation of the inner wall, economy, the display of greater magnificence, or for any other reason.8

This argument is reiterated in Style, but the term ‘enclosure’ is substituted for the term ‘space’. Weaving becomes associated with establishing domestic space, ‘the means to make a “home,” the inner life separated from the outer life’. Once more, Semper stresses that weaving preceded the solid wall and that the textile wall and space are independent from the (load-bearing) construction. One can

The Tectonics of Brick Architecture

7 It may be assumed from Semper’s later theory that ‘elements’ in this context should not be read as ‘material elements or forms, but rather as “motives” or “ideas”, as technical operations based in the applied arts,’ as Harry Francis Mallgrave has pointed out. See Harry Francis Mallgrave’s introduction in: Semper, Gottfried, The Four Elements of Architecture and other Writings, Cambridge / New York, 1989, p. 24

8 Semper, Gottfried, The Four Elements of Architecture, in: ibid., p. 104

Tectonics of Cladding

Copperplate engraving 2, from Karl Boetticher, Die Tektonik der Hellenen. Bötticher shows how he imag-ined the derivation of the Doric, Ionic and Lesbian cyma: The weight of the abacus is bending down a row of leaves. In Bötticher’s view this is a symbol of the load-bearing and the load-borne in conflict.

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Semper’s focus on ‘use, material, tools and procedures’ entailed that he was often accused of technical determinism and later even viewed as a predecessor of functionalist thought in the modern movement. This however has to be put in perspective. Semper considers ‘use, material, tools and procedures’ as important aspects in the becoming of artistic form, but not as the sole factors. Moreover Semper does not advocate the expression of technical aspects in artistic form. On the contrary, tectonics of dressing, rather, favours the mastery of technical constraints and technical necessities in such a way that all tech-nical aspects of form-making become invisible. Semper articulates this concern in an oft-cited passage on masking as a principle in arts, curiously placed in a footnote:

But masking does not help when the thing behind the mask is not right or when the mask is no good. If the material, the indispensable, is to be completely destroyed in the artistic creation in the sense meant here, then the material must be completely mastered. Only complete technical perfection, only the judicious and proper treatment of the material

even detect an attitude here that opposes the idea of expressing the load-bear-ing structure: ‘Scaffolds that served to hold, secure or support this spatial enclosure had nothing directly to do with space or the division of space. They were foreign to the original architectural idea and were never form-determin-ing elements to start with.’9 Semper supports his argument by pointing to the etymology of words denoting spatial enclosure in Germanic languages. It turns out that they all have a textile root. Semper gives examples such as Decke (ceiling, cover), Bekleidung (cladding, dressing), and the similarities between Wand (wall) and Gewand (robe) and Zaun (fence) and Saum (seam). Semper argued that the earliest dwelling enclosures had an origin in textile. For Semper, this origin constitutes the essence of the wall as a formal principle and should be maintained even if the material from which the wall is built changes. Semper cites Assyrian and Greek stonewalls, which were covered with wooden panels containing textile motives, as examples. In contrast to Bötticher’s tectonics of load-bearing, which means that the (ornamental) appearance of a building should refer to the structural forces at work in its physical building elements, Semper conceptualizes a tectonics, which I should like to refer to as the tectonics of dressing. It is concerned with the ‘constructedness’ of the dressing itself. In Style Semper examines the ‘becoming’ of form from two points of view. The first is concerned with the influence of the ‘material service or use that is intended, whether actual or presumed, and taken in a higher symbolic sense’.10 Semper considers this a timeless aspect of form, which he explores for each craft in a chapter with the subtitle ‘General-Formal’. The association of the wall’s origination with the textile craft implies for Semper that the gen-eral-formal aspects of textile should be responded to in the design of walls and façades also today. They should always refer to the formal DNA of textile, the first spatial enclosures. The second point of view that Semper deals with in Style concerns the ‘becoming’ of form and the influence of ‘the material used to produce it, as well as of the tools and procedures applied’. In contrast to the timelessness of the general-formal aspect this aspect of form changes with historic time and geographic place. Each craft is dealt with in a chapter with subtitle ‘Techni-cal-Historical’.11 The technical-historical aspects of form are considered a reason for stylistic differences as well as the motor of stylistic evolution.

The Tectonics of Brick Architecture

9 Semper, Gottfried, Style in the Technical and Tectonic Arts, or: Practical Aesthetics, Getty Research Institute, Los Angeles 2004, p. 248.

10 Semper, Style, p. 107. 11 A third pole is the aesthetic concept that complies with the general laws of beauty, and the (genius)

architect with his individual inclinations.

Tectonics of Cladding

Plate from Gottfried Semper, Der Stil, § 59 Relation of Costume to Architecture, ‘Another connection [ between costume and sculpture] is clearly evident in the shape of Egyptian capitals illustrated here: they are decorated with lotus blossoms inserted in the same way that ladies of that country ornamented their heads by fastening stalks of these flowers in their hair or behind their ears.’

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have a closed appearance similar to battlements. The constraints are especially felt with the treatment of entrance and window openings. Instead of plasticity, we get nuances of colour in the wall surfaces, which are often subdivided by arches, and, in addition, the white plaster of the backgrounds (in friezes, niches, windows) create a strong contrast. […]15

The first masons were actually stonecutters, who initially transferred building conventions associated with natural stone to brick.16 Often, decorative ele-ments were still executed in natural stone. Dutch architecture in the period 1500 to 1700 was still characterized by the combination of brick and natural stone, which was employed in the well-known horizontal layers (the Dutch call them ‘layers of bacon’, as they resemble the contrasting stripes in bacon), cornerstones and tympanums. Eugen Gugel was a German architect and the first to be appointed pro-fessor of architectural design in the Netherlands at the Polytechnical School of Delft in 1862 (today TU Delft). He made a link between the German tectonic debate and the brick architecture of the Dutch Renaissance. His 1869 book on the history of building styles throughout architectural history, Geschiedenis van de Bouwstijlen in de Hoofdtijdperken der Architectuur, is indebted to Böt-ticher’s Tektonik.17 Gugel appreciates the architecture of the Dutch renaissance for the expression of tectonic qualities in the brick façades. He cites as examples of this the relieving arches above window and door openings, and the deco-rative brick patterns in the load-free fields below arches.18 This characterization most notably applies to town halls, guild houses and domestic architecture. Domestic architecture in the Low Countries was originally a wood construction erected by carpenters who also happened to be shipbuilders. In the 15th century, it became obligatory for partition walls in cities to be made of brick. When brick gradually also replaced the wooden cladding of the façades, brick craftsmanship was used for representative purposes. Besides bricklaying in a proper bonding pattern, brick craftsmanship meant making arches (semi-circular arches, segmented arches, Dutch or strait arches, bas-ket-handle arches) and diverse forms of adornment such as accompanying rows of brick above porticos and window openings, the bending of runners,

according to its properties, and above all only the consideration of these properties in the act of shaping form can cause the material to be for-gotten, can liberate the artistic creation from it […]12

FROM TECTONICS TO BRICK TECTONICS Both Bötticher’s and Semper’s accounts of tectonics were actually dis-courses on ornamentation. In Bötticher’s tectonics of load-bearing, the orna-mental dress is an idealistic representation of the structural forces at work in the physical building parts that are covered by this ornamentation. In Semper’s tectonics of dressing, the ornamental dress refers to the formal principles that are implied by the construction of the textile dressing itself and came into being with the emergence of the textile arts, the original spatial enclosures. Bötticher bases his theory on observations of ancient Greek temples. These were built in natural stone and covered with a layer of stucco. Semper observed that this layer of stucco was originally colourful. He believed that constructing something in solid stone with a dressing of stucco was the ideal way of building. Such structures were thoroughly solid and durable, while the colourful pigments of the dressing achieved an almost immaterial state of being. The appearance of the building was therefore freed of most technical constraints.13 Neither Bötticher’s nor Semper’s writings about tectonics deal with brick as a building material in particular. This section discusses the impli-cations of brick as a material. In Europe north of the Alps, the use of brick emerged between the 12th and 14th centuries, first in some church buildings, where the use of natural stone had been common up till then. Using brick instead of natural stone means limiting the expressive possibilities.14 The dictionary entry that prompted these reflections has the following to say about brick as a material:

[…] The nature of the building material [brick] implies that mouldings are kept simple, straight and inside the building volume, and that a number of decorations (such as small free-standing colonnades, pin-nacles, finials, crockets) are only used by exception. Parapets and suchlike

The Tectonics of Brick Architecture

12 Ibid., p. 439. 13 Natural stone covered with a layer of stucco dressing constitutes for Semper the ideal building

material. I have argued elsewhere that this thought leads to a deadend for the evolution of form and constitutes a contradiction in Semper’s theory. Garritzmann, Udo, From the Colour of Dressing to the Dressing in Colour and Back Again, in: Komossa, Susanne, Rouw, Cees, Hillen, Joost, eds. Kleur in de Hedendaagse Architectuur / Colour in Contemporary Architecture, Amsterdam 2009, pp. 172–197.

14 The emergence of brick in Northern Europe happened simultaneously in several nuclei independ-ent of each other. It is assumed that members of certain convents brought the knowledge of brick-making from visits to branch convents south of the Alps back to Northern Europe. See: Perlich, Barbara, Mittelalterlicher Backsteinbau in Europa: Zur Frage nach der Herkunft der Backsteintechnik, Imhof, Peters-berg, 2007.

15 Haslinghuis, Janse, Bouwkundige Termen, Verklarend Woordenboek van de Westerse Architectuur- en Bouwhistorie, Leiden 2005, 5th edition, p. 47, (1997, 1st edition), translation by the author.

16 Perlich, Barbara, Mittelalterlicher Backsteinbau in Europa: Zur Frage nach der Herkunft der Backstein-technik, Imhof, Petersberg, 2007.

17 Gugel refers not only to Bötticher but also to Semper. It seems that he was not concerned about the conceptual differences held by these two authors.

18 Brouwer, Petra, De Wetten van de Bouwkunst, Rotterdam 2011, pp. 313–318; Petra Brouwer actually points out that this positive evaluation of Dutch renaissance architecture only occurred in the second and later editions of Gugel’s Geschiedenis.

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eaves friezes, arched friezes, band friezes such as saw-tooth frieze, console frieze, dog-tooth course, rowlock course, soldier course, pilaster strips and plinths, linings with brick patterns. The well-known Dordtse Gevel, a type of façade developed in the city of Dordrecht between the 16th and late 18th centuries, is an excellent example of a representative brick façade. Building a Dordtse Gevel was considered a ‘masterpiece’ that would allow masons to become master craftsmen as it comprised all the trade’s necessary techniques. Most prominent was the acute brickwork of a decorative clover pattern in the field beneath the window arch. The Dordtse Gevel perfectly illustrates the tectonics of load-bearing that Gugel appreciated in the Dutch renaissance style. In terms of load-bearing, it is interesting to note that the Dordtse Gevel does not display the mason’s craft on the ground floor, but on the levels just above. This can be explained by the fact that the ground-floor façade in Dutch architec-ture of that period (the Dutch have a separate word for it, pui, which is often a shop front) remained often the territory of the carpenter. The representative brick façade rests on a wooden sub-structure, a bressumer supported by posts, ‘floating’ above the ground floor. If the brick façade started to lean, as it sometimes did to compensate for the previous wooden façade’s floor-by-floor stepped can-tilever effect, wooden beams also counteracted the additional horizontal forces. When the tectonics of load-bearing turns to brick as a material, it does not express the actual structural forces working in the various building parts as much as the ornamentation of a Greek temple would. It rather articulates the presence of various building parts that fulfil different structural functions. A brick façade according to the tectonics of load-bearing is structured by the expression of floors and walls, of posts and lintels, and of supporting and supported building parts. It is more difficult to find historic examples of the brick tectonics of dressing in the Netherlands. But to start with, one could say that all bonding patterns resemble textile patterns in the first place. They develop a formal motive (the bonding pattern) from the technical necessity of joining the bricks, just as weaving patterns emerge within the technical constrains of warp and weft.19 The use of two contrasting colours of brick intensifies the resemblance of the bonding patterns to ones used in textile. The most decorative brick patterns, in which the function of the bonding is subordinate, evoke the stron-gest association with textile patterns. In regard to the tectonics of load-bearing in the Dutch Renaissance discussed above, one might add that it is the tectonics of dressing with its contrasting decorative brickwork that facilitates the reading of the other brickwork as load-bearing.

The Tectonics of Brick Architecture

19 It is probably difficult to maintain that in Northern Europe bonding patterns indeed developed with the impetus of textile representation, as Semper would have argued.

Tectonics of Cladding

Example of the Dordtse Gevel with tectonics of load-bearing in the brickwork. Note that elaborate brickwork starts only from the first floor upwards; on the ground floor it is supported by a wooden substructure.

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These decorative textile brick patterns can be part of a façade according to the tectonics of load-bearing, as we have seen in the example of the Dutch Renaissance. Earlier 14th-century examples of decorative textile brick patterns in the Netherlands are to be found in the Petruskerk in Zuidbroek, the Maria-kerk in ‘t Zandt, the Donatuskerk in Leermens and the Petrus en Pauluskerk in Loppersum, all in the province of Groningen. I am not aware of early brick tectonics of textile in the Netherlands that cover larger parts of a façade, such as can be found in Persian architecture. Examples include the minaret of the Friday Mosque in Damghan (11th cen-tury), the Tomb of Sheik Shibli in Damavend (12th century) and the Arg of Karim Khan in Shiraz (1776–1777). The first brick buildings in the Netherlands to use the tectonics of dressing across the entire mass of a building seem to belong to the Amsterdam School, a movement that emerged contemporaneously with modernism. The latter embraced the new construction methods that used steel and reinforced con-crete in search of a completely new aesthetic devoid of ornament and decoration. The Amsterdam School, by contrast, seems to have enjoyed the new decorative possibilities rendered possible for brick by the new construction techniques and non-bearing façades. Its buildings are characterized by unconventional bonding patterns in various combinations, as well as the exploration of brick’s sculptural possibilities to sometimes extravagant extremes. This resulted in dynamically shaped building volumes with a strong overall monumentality that were nonetheless highly picturesque. The Amsterdam School, which was itself a reaction against the prevailing rationalism of Berlage, was later in turn criticized for its irrationality and straining for a picturesque effect that accepted the disengagement of the façade from the plan. One of the critics was the architect Ad van der Steur, who characterized the decorative use of brick related to the Amsterdam School in the Boymans Museum’s 1941 catalogue. ‘Brick is no longer used as a constructive material,’ wrote Van der Steur, ‘but has a merely decorative function, in which the lim-itation of a straight surface is modified into an erratically formed enclosure. Moreover, toothing, wall projections, and even suspended brick ceilings have been introduced … The strange material usage in the post-war period is related to a desire for abundance, [and] the frivolity of those days that also led to Dadaism. It does not have a deeper social meaning, which explains why this movement disappeared as promptly as it appeared.’20 But the tectonics of dressing and its decorative use of brick does not necessarily imply the sculptural eccentricity that the Amsterdam School employs.

The Tectonics of Brick Architecture

20 Van der Steur, Ad, De Baksteen tusschen 1890–1940, in: Museum Boymans Rotterdam, Nederland Bouwt in Baksteen 1800–1940, catalogue, Rotterdam 1941, p. XVIII + XIX (translation by the author); also: H. M. Kraayvanger, De Nederlandsche Bouwkunst na Berlage, in: ibid., p. XIII.

Tectonics of Cladding

Mariakerk, ‘t Zandt, province of Groningen, 13th century

Museum Boymans, Rotterdam (1928–1935). Architect: Ad van der Steur

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The fact that the brickwork is (in part) load-bearing does not contradict its classification as the tectonics of dressing. What matters is the aesthetic appear-ance of the brickwork, not whether it really is load-bearing. The unconventional decorative bonding pattern with its pattern on a medium scale is important for adding detail to the large, otherwise mostly unstructured façade. The absence of piers on the large surfaces of the exterior brickwork as well as the almost flush detailed windows supports the allusion to the tectonics of dressing. The building of the Netherlands Trading Society in Rotterdam (1941–1950) by C. Elffers and A. A. van Nieuwenhuyzen is another example but in a more traditional style. It is one of a few bank buildings that were among the first post-war constructions in the city of Rotterdam, and it contrasted starkly with the modernist style of the time. The bank building resembles a monolithic brick mass with façades structured by what at first sight look like conventional pilasters comprising two windows. On closer inspection, however, one realizes that the building mass continues above and below the pilasters, which do not rest on the ground. Rather, they appear to be attached to the building mass like a large textile network. Also, the brickwork between the pilasters protrudes from the main mass of the building as if attached like dressing. The breastwork is articulated as a frame filled with decorative brickwork resembling diagonally interlacing textile bands. Other examples of unconventional bonding patterns, which achieve a characteristic decorative pattern all-over, are the Unilever office building (1930) by H. F. Mertens and the St. Dominicus church (1957–1960) by Evert and Herman Kraayvanger, both in Rotterdam. The brick tectonics of dressing develops the articulation of the façade from the ‘constructedness’ of the dressing itself. It realizes its aesthetic concept through the technically necessary joining of bricks. The brick tectonics of dressing explores the creation of decorative patterns on a smaller and on a larger scale. The bricks can be stacked in all possible directions for this purpose. The effect of decorative pattern making is enhanced through the use of bricks of different sizes, kinds and colours and the careful employment of relief.

INTERMEZZO: TECTONICS AND THE CHALLENGE OF EXPANSION JOINTS The introduction of thermal wall insulation, which happened approx-imately in the 1970s as a consequence of the first oil crisis, caused — liter-ally — cracks in brick façades.22 The thermal detachment of the brick dressing from its load-bearing substructure causes differences in thermal deformation

North German Expressionism, a counterpart of the Amsterdam School espe-cially influential in Hamburg, Bremen and the Rhine–Ruhr region, uses the tectonics of dressing in its brickwork to similar decorative effect, though less erratically and with more restraint in most of its buildings. There are more discreet examples of the tectonics of dressing in the Netherlands, such as Museum Boymans (1928–1935) with its beautiful variation of the monk bond by the aforementioned Van der Steur. A present-day beholder would expect its decorative bonding pattern to consist of two stretchers and two headers for a course of conventional height, and alternating stretcher and header for a course with bricks on edge. However, what appear to be bricks on edge are actually bricks with the height of a double course. Indeed, the brick walls happen to be load-bearing in conjunction with concrete auxiliary constructions. Van der Steur himself classifies the use of brick in his museum as ‘purely structural’, ‘with additional concrete structures’, such as ‘floors, and additional wall reinforcements made of light concrete pillars that can reduce the load of the walls.’21

The Tectonics of Brick Architecture

21 Ibid., p. XVI + XVIII 22 This at the time new phenomenon influenced our aesthetic experience of more than just brick

façades.

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The building of the Netherlands Trading Society, Rotterdam (1941–1950). Architect: C. Elffers and A. A. van Nieuwenhuyzen

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between the two. Various façade segments may also settle in different ways, because different loads are put on the supporting substructure. If the façade segments are not given enough space to move, cracks inevitably follow. It took a little while for the implications of thermal insulation to be fully understood. The solution to the crack problem was to provide sufficient expansion joints along the façade. In the Netherlands, the technical require-ments for expansion joints are compiled in two recommendations for the construction of brick façades and stone constructions compiled by the con-sultancy CUR.23 It seems, however, that in most buildings one evil is cured by another. The brick façade that used to have a continuous surface, suggesting a mono-lithic building volume, is now cut into pieces that are separated by numerous expansion joints filled with mastic. In most cases, expansion joints appear to be the solution for a technical requirement that is only thought of in hindsight. It seems they are forced on the brick façade when it is too late for aesthetic

The Tectonics of Brick ArchitectureTectonics of Cladding

Unilever office building, Rotterdam (1930). Architect: H. F. Mertens

St. Dominicus kerk, Rotterdam (1957–1960). Architect: Evert and Herman Kraayvanger

23 CUR-Aanbeveling nr. 71, Constructieve aspecten bij ontwerp, berekening en detaillering van gevels in metselwerk (CUR Recommendation no. 71, Constructional aspects in the design, calculation and detailing of brick façades) and CUR-Aanbeveling nr. 82, Beheersing van Scheurvorming in Steenconstructies (CUR Recommendation no. 82, Control of crack formation in stone constructions).

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It is interesting to note a contradiction in the relationship between the tectonics of load-bearing as articulated in the façade and the actual presence of the load-bearing structure in the building. Contemporary building techniques (mostly reinforced concrete) allow for much bigger spans than are appropriate for façades built upon classical principles. Therefore, pilasters can suggest the presence of a load-bearing structure when in fact there is none. Hans Kollhoff solves this contradiction by adopting a modification of Semper’s principle of dressing that was originally introduced by Adolf Loos. In Kollhoff ’s words: ‘The aim is not the visualization of the construction itself, but that which reminds us of it. […] If Loos talks about construction, he means the appearance of construction, totally independent of the actual constructional circumstances. […] The seemingly antagonistic pair, appearance and construc-tion or art and technique, is viewed as something complementary.’26 The tectonics of load-bearing of this particular position is not about honesty of construction, but about the remembrance or assumption of a load-bearing construction that is supposed to make sense to the human sen-sory system. As such, it adopts the tectonics of dressing’s principle of masking, however with a different prefix. The tectonics of dressing does not want to be reminded of the load-bear-ing structure, even if a load-bearing structure is present, nor does it want to be reminded of any other technical necessities. It achieves the first by masking the load-bearing structure. It achieves the second by the complete technical mastery of the mask’s construction. The tectonics of load-bearing, by contrast, wants to be reminded of the load-bearing structure according to the position of Hans Kollhoff, even if it is not present. If necessary, its art form corrects the core form. A mask of load-bearing tectonics can camouflage the absence of a core form. Both the tectonics of load-bearing and the tectonics of dressing are concerned about the appearance of a building in relation to its construction. The tectonics of load-bearing is concerned about the appearance of a building in relation to its load-bearing structure; the tectonics of dressing is concerned about the appearance in relation to the construction of the dressing itself. The tectonics of load-bearing is a position that is consciously pursued by a particular group of architects. Does this mean that most other architects adhere to ‘Semperian thinking’, consciously or intuitively? This seems rather unlikely. Certainly it is true that all buildings in our part of the world, where thermal insulation is an obligation, are technically dressed. This has also created tremendous freedom for the design of façades, and sometimes this has resulted in a technically disengaged position. But this cannot be the outcome

considerations. Currently expansion joints are the biggest challenge to brick tectonics, whether load-bearing or dressing. The design of a brick façade in the pre-expansion joints era focused on the composition of the open and closed parts, and any protruding or receding elements, that had to be brought into accordance with the modular sizes of the brick and bonding pattern used. Today, the additional pattern of numerous expansion joints has to be considered as well. An aesthetically satisfactory brick façade incorporates the design of the expansion joint pattern into the aesthetic concept of the whole façade. In other words, the expansion joint pattern should not be viewed as a technical necessity, but as part of the overall aesthetics. The following quote from ‘Textiles: A. General-Formal’ in Semper’s Style describes a formal principle that holds true for brick bonding patterns and should also be applied to the assemblage of the dilatated ‘tectonic’ plates.

A most important and prime axiom for artistic practice is most simply, most originally, and at the same time most cogently expressed in the seam — the principle of making a virtue out of necessity. It teaches us that anything that is and must be patchwork, because the materials and means at our disposal are insufficient, should not be made to appear otherwise. If something is originally separate we should characterize it not as one and undivided but, by deliberately stressing how the parts are connected and interlaced toward a common end, all the more elo-quently as coordinated and unified.24

THE TECTONICS OF LOAD-BEARING AND THE TECTONICS OF DRESSING TODAY Hans Kollhoff is probably the most important inspiration for contem-porary architects associated with the tectonics of load-bearing. In 1991, he organized a conference Über Tektonik in der Baukunst (On tectonics in the art of building).25 In his own contribution, Hans Kollhoff advocated renewed attention on the interdependency of appearance and construction, in which the appearance of a building should appeal to the human senses by evoking a tectonic feeling based on gravity and solidity. In retrospect, the conference seems to have been the foundation for Kollhoff ’s work in the ensuing years. Increasingly drawing on the classical tradition, Kollhoff addresses contemporary prefabricated building techniques and develops his tectonics of load-bearing in a bas-relief façade system. By organizing the classical elements of architecture in such a bas-relief, the expan-sion joints are disguised by letting the ‘tectonic plates’ slide over each other.

The Tectonics of Brick ArchitectureTectonics of Cladding

24 Semper, Style, p. 154. 25 Kollhoff, Hans (ed.), Über Tektonik in der Baukunst, Braunschweig / Wiesbaden, 1993. 26 Ibid., p. 15, translation by the author.

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of Semperian thinking, as I hope the argument of this essay makes clear. Semper’s tectonics of dressing is certainly not free of engagement when it comes to the actual construction of a façade. Designing a brick façade according to the tectonics of dressing, without, however, subscribing to the expression of load-bearing, is a challenge that has not been taken up by many contemporary architects yet. The number of build-ings mentioned in this publication that fall under the tectonics of load-bearing seems to confirm this. Perhaps architects who are inclined to engage in tectonic thinking find the load-bearing approach more productive, more fruitful and / or more practical than the dressing approach. Perhaps this is due to the shift in scale that occurs once an entire building is conceived with the tectonics of dressing. The tectonics of load-bearing draws upon classical elements of architecture that also include medium-scale elements. This medium scale is yet to be devised for the tectonics of dressing. Perhaps it is also the legacy of Dutch modernism with its tradition of rationality that makes the tectonics of load-bearing more appealing than the tectonics of dressing, which finds pleasure in decorative patterns that cannot necessarily be rationally justified. In any case, there seems to be huge, as yet unexploited potential for the tectonics of dressing. If architects who do not necessarily subscribe to the tectonics of load-bearing were nonetheless to explore the interdependency of appearance and construction with as much energy and success as their supposed antagonist, one could look forward to a vivid diversification of the culture of brick tectonics.

Tectonics of Cladding

Brickwork has been used as construction system for more than 10,000 years. The most incredible structures have been built with it, but furthermore, all over the world simple brick houses can be found. The use of brick has also lead to beautiful buildings in the Netherlands, in which the craftsmanship of both architects and masons has been constitutional. The possibilities of con-struction in brickwork were primarily based upon empirical knowledge until the end of the 19th century. It was only towards the end of that century that a shift took place in the Netherlands towards rationalisation and even scienti-fication of architecture and construction1. In the same period new inventions like the brick cavity wall enter the building practice and from the start of the 20th century legislation and regulations start to have a significant influence on architecture and construction. This timeline gives a chronological overview of the change in legislation and regulations and the application and production of brickwork in the Neth-erlands. The first legislation and regulations (Housing Act and Model Building Regulations) were still primarily based on the improvement of the basic quality of dwellings. It is, however, the moment that influence starts to be exercised in terms of legislation and regulations on the design and construction of brick-work. Whereas the first building regulations for the implementation of the Housing Act were still relatively brief about masonry constructions, the later versions imposed increasingly more regulations and preconditions. The Tech-nische Grondslagen voor Bouwvoorschriften (Technical Principles for Building Regulations) from 1955 proved to be a decisive step in this process. At first instance, it was still a somewhat artificial way of connecting construction theory and practice. This was, however, continued in terms of the development of specific masonry standards and other, direct and indirect influential reg-ulations on masonry construction. The increasing production, as well as the

Harrie Vekemans

LEGISLATION AND BRICKWORK FAÇADES

IN A HISTORICAL PERSPECTIVE

Brick. An Exacting Material

1 See the book: De wetten van de bouwkunst (The Laws of Architecture) by Petra Brouwer

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The use of brick has risen remarkably in Dutch architecture since the end of the last century. The rediscovery of this age-old material coincided with an (inter)national heyday, which Bart Lootsma framed in the book Superdutch.1 The book is characteristic of a period with great appreciation for distinctive building concepts in which the unique and photogenic image of the building plays an important role. The book contains approximately forty-five buildings only one of which, strangely enough, is executed in brick. Set against the back-ground of Superdutch, the uniformity of brick buildings is particularly striking. This uniformity may explain the absence of the material in the book, but the architects who have been building with brick since the 1990s are certainly not unconnected from the spirit of the times. They are also interested in the con-cepts and individual expression of their buildings. This leads one to suspect that the aforementioned uniformity of brick buildings has its origins elsewhere. It raises the question of how this has come about: why does a brick building look the way it does? This question sparked off the analysis, conducted with students of the Amsterdam Academy of Architecture, of fifteen Dutch brick buildings con-structed after 1994.2 By examining and redrawing the original architects’ drawings, the way these buildings were constructed is revealed. The survey offers insight into the influence that structural preconditions and the tendencies of contemporary building practice have on the design strategies of architects.3

Brick. An Exacting Material

BRICK DRESSESJan Peter Wingender

1 Superdutch: New Architecture in the Netherlands, Bart Lootsma, Thames & Hudson, 2000. 2 The analyses were previously presented in the exhibition Brick Dresses held in 2010–2011 at the

Amsterdam Academy of Architecture, VKO Ceramics Centre Velp, de Dag van de Bouwkeramiek (The Day of Building Ceramics) Amsterdam, Eindhoven University of Technology, the Amsterdam University of Applied Sciences and MADE Tilburg.

From spring 2010 to summer 2012, students from the Amsterdam Academy of Architecture made digital models based on drawings. In this way, they painstakingly united the role of draughtsman, structural researcher and digital building contractor. Without their work, the exhibition and this publication would not have been possible. Special thanks to: Laura Achterberg, Narda Beunders, Elizabeth Bonavera, Jesse de Bosch Kemper, Pascal Hennebergue, Marjan van Herpen, Margot van Honert, Monique Hutsche-makers, Mark Keizer, Matic Pajnik, Femke Popinga and Ivar van der Zwan.

3 The concept of design strategies comes from Rafael Moneo’s Theoretical Anxiety and Design Strategies in which he clarifies design strategies as: ‘refer[ing] to the mechanisms, procedures, paradigms, and formal devices that recur in the work of architects’. The architects whose work is included in the analysis have built an important part of their oeuvre in brick. Through in their practice, knowledge, experience and discoveries are passed from one project to the next, which make the strategic design approach with regard to brick possible.

Rafael Moneo, Theoretical Anxiety and Design Strategies in the Work of Eight Contemporary Architects, The MIT Press, Cambridge, MA, 2004, ISBN 0-262-13443-8.

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It uncovers the distinctive patterns and dilemmas underlying the apparent uniformity of brick, and it poses a question about the possibilities architects derive from that same uniformity? Because, upon closer inspection, the dif-ferences in the use of the material by architects appear to be remarkable. This essay bears on the survey and focuses on the collective domain of our profession, the intersection of building techniques and architectural design. But to understand the recent revival in the use of brick, we must first take a step back in time.

A QUIET REVOLUTION The rich history of building in brick was presented at the exhibition Nederland bouwt in Baksteen 1800–1940 (The Netherlands Builds with Brick 1800–1940) held 1941.4 The exhibition at Museum Boijmans in Rotterdam celebrated an exemplary Dutch building material and its significance for national architecture. The timing and the location of the exhibition were, however, unfortunate. The trauma of the neighbouring bombed city centre and the subsequent occupation in combination with the alleged nationalistic tone of the exhibition backfired on the curators, particularly Dirk Hannema, the director at that time. In retrospect, the exhibition represented a turning point. Brick, the pre-eminent national building product, which had been unequivocally exalted up until that moment, became increasingly entangled in the postwar controversy between modernity and tradition. Furthermore, brick was connected with conservatism and nationalism in that controversy. It was positioned as a material that did not deserve a place in modern, for-ward-looking architecture. However, the actual use of brick was not, of course, over and done with; the scale of postwar reconstruction was simply too great and the methods of building too pragmatic for that to happen. As a conse-quence, brick was frequently, yet silently, used. The rich prewar tradition of brick construction continued far into the 1950s and played a large role later in the architectural movement of the Bossche School. However, reflection on the use of the material increasingly retreated into the background in prevailing Dutch postwar architecture debates. In the midst of this silence, the architectural application of brick changed drastically. The use of brick for foundations, primary load-bearing structures, façades, interiors and civic works is still clearly visible in photos from the bombed centre of Rotterdam. Brick was a multi-faceted building material with a broad structural and architectural significance, but this changed quickly. By the end of the nineteenth century, the cavity wall had already been introduced into

Brick Dresses

4 Nederland bouwt in baksteen 1800–1940 (The Netherlands Builds with Brick 1800–1940), Museum Boymans van Beuningen Rotterdam, 1941.

Introduction

Cover from: Nederland bouwt in Baksteen 1800–1940, Museum Boymans, Rotterdam (1941)

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Dutch building practice, and, as a result, a separation arose between the main load-bearing structure and the cladding of a building: a fundamental distinction in architecture that was commented upon in those years by Adolf Loos.5 This distinction between structure and cladding was more marked in postwar build-ing practice in the Netherlands as a result of the increasing use of concrete for foundations and load-bearing structures. The distinction between structure and cladding also became a difference in material: concrete for the structure and brick for the cladding. With the introduction of insulation in the cavity wall in the 1970s, the distinction between structure and cladding also assumed a thermal character. Buildings evolved into a warm, insulated concrete load- bearing structures fitted with a cold, rain screen brick jacket.6 Brick silently changed between 1960 and 1980 from a multifaceted building material into a frequently used cladding material. Our brick buildings became brick dresses. Since the 1980s, the use of brick has generated interest from a gener-ation of architects who are not directly connected with the postwar controversy. In a focused quest for the historical anchoring of architecture, the interaction with the existing city received increasing attention.7 This was particularly related to a change in the type of assignment architects were undertaking, which extended extended from the building of new districts to the renewal of the existing city and the redevelopment of harbour fronts and city centre industrial areas. Brick turned out to be a useful material for the new generation of architects in achieving a connection between the existing city and the new developments and expansions. At the same time, technically superior ranges of brick became available from the brick industry, and the choice of colour, texture and size of bricks increased considerably. The industry promoted the material directly to architects with the campaign mooi is gemetseld in baksteen (beauty is dressed in brick).8 Brickwork remained easy to execute for contrac-tors, and the prices for materials and processing remained stable and predict-able. There was also a renewed interest from clients in the material due to its low maintenance and the fact that it ages well, but especially because brick was still appreciated by the Dutch private clients who would have to buy a large proportion of the newly constructed houses. All these factors made the

Introduction

5 In particular, in his essay Das Princip der Bekleidung from 1898 / Adolf Loos, Gesammelte Schriften herausgegeben von Adolf Opel, 2010 Lesethek Verlag.

6 For an overview of structural development, see: H. Veenemans, De techniek achter het stapelen: overzicht historisch perspectief 1912–2012 (‘The Technique Behind Stacking: Overview Historical Perspec-tive 1912–2012’). Included in this publication.

7 See also the interviews in Rogier van den Berg’s text Hoe de baksten en het ambacht terugkeerde in de Nederlandse stedenbouw (‘How Brick and Craftsmanship Returned to Dutch Urban Planning’). Included in this publication.

8 For this development, see also Louise Schouwenberg’s text ‘The City Tells Stories’. Included in this publication.

Brick Dresses

Bombed city centre, Rotterdam, 1941

Bombed city centre, Rotterdam, 1941

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Brickwork is no longer about structure, but unavoidably evokes the image of structure as a result of its historical appearance. We thus arrive at a classical theme in architecture, namely the expression of the law of gravity by means of a structure in the façade of a building. In 1991, the architect Hans Kollhoff addressed this theme during his sym-posium Tektonik. Bau-Kunst Heute? and in his contribution Der Mythos der Konstruktion und das Architectonische.12 In his lecture, Kolhoff discussed the relationship between the structure and the cladding of a building.

‘Die Bekleidung als Haut ist Teil des Körpers und damit gestalterischer Willkür entzogen. Die Haut steht in einem delikaten Verhältnis zur Kon-struktion. Diese wird nicht zur Schau gestellt und nicht zugedeckt. Sie scheint durch, im wörtlichen und übertragenen Sinn. Ziel ist nicht die Visualisierung der Konstruktion an sich, sondern das an sie Erinnernde’.

Kolhoff emphasises the role of the observer and his or her perception. The aim is an execution of the façade that evokes a memory of the underlying structure and spatial construction of a building. In the words of Kollhoff, ‘they shine through’. With regard to brickwork façades, this relationship between cladding and structure is evident as a result of the historical use of the mate-rial — and the memory of the structural use. The size of the bricks and the stacking of them into brickwork is a way of building that allows one to ‘imagine’ easily. The observer can easily relate to the façade of a building in a physical sense and imagine how a structure of a building is made. The degree to which the ‘way a structure shines through’ is a theme that keeps returning in the projects in this book. As a result of its historical significance, the material obviously challenges architects to take a position. When designing brick façades, the position that architects take varies. These positions can be clarified on the basis of the nineteenth-century discussion which architecture historian Petra Brouwer cites in her study De wetten van de bouwkunst, Nederlandse Architectuurboeken in de negentiende eeuw (The Laws of Architecture, Dutch Architecture Books in the Nineteenth Century).13 In that discussion, the origin of ‘real architecture’ is traced back to three archetypes: the cave, the hut and the tent. The originator of this school of thought was Quatremère de Quincy. He introduced the three archetypes as the source of three ‘systems of constructions’. The three archetypes can be placed alongside the previously made distinction of ‘Massiv- en Filigranbau’

material interesting for the sharply increasing building output from 1990. The favourable reception for Piraeus, a residential building in the Eastern Docklands in Amsterdam by Hans Kollhoff and Christian Rapp9 can be seen as a sign of the broader re-appreciation of brick. From that time, the use of brick represents a theme that forms the basis for the development of the signature style of a generation of architects. They formulated, in practice, an answer to the postwar quiet revolution with new architectural strategies for the use of brick as a cladding material. This shift in the use and significance of the material raises the question whether the structural role of brick, in its metaphorical and literal meaning, has also been truly exhausted as a result?

THE CLADDING OF THE CONSTRUCTION In ‘Massive- und Filigranbau’ (‘Solid and Filigree construction’), the introduction to Constructing Architecture, a handbook10, Andrea Deplazes reduces building to two approaches that are complementary from a structural and constructional viewpoint: the Massivbau (solid construction), which arises from structural stacking of modules — for example, with natural stone blocks — and Filigranbau (filigree construction), which arises from combining a skeleton with cladding. Brickwork belongs, historically speaking, to solid construction, since it is created by stacking bricks. Brick structures and spans in the form of vaults are comparable with those made from natural stone. However, it is the development of the cavity wall that also includes brick as cladding under the category of filigree construction, with a distinction between structure and cladding. As a result, brick has become an ambivalent material. It plays on both building traditions simultaneously. Architects make grateful use of the confusion arising from this. Terms like ‘permanence’, ‘robustness’ and ‘sturdiness’ easily find their way into the explanation of contemporary buildings with brickwork façades. In his essay Firmitas,11 Jacques Herzog provides a critical commentary on this phenomenon: ‘Firmitas wouldn’t be a separate category on the same level as venustas but rather a special case, an absolute value that cannot be achieved, that will remain a dream and is interesting only as such.’ Brick hints at the structure of a building, and Herzog is, of course, correct when he states that this has become part of façade design.

Brick Dresses Introduction

9 Piraeus, Levantkade Amsterdam. Design Hans Kollhoff with Christian Rapp. Commissioned by Woonstichting De Doelen (De Doelen Housing Association) Amsterdam. Design 1989–1991, execution 1991–1994.

10 Andrea Deplazes, ‘Massiv- und Filigranbau’, in Architektur Konstruieren vom Rohmaterial zum Bauwerk, Ein Handbuch. Birkhäuser Verlag, 2005, ISBN 3-7643-7188-9

11 Edited version of a lecture held by Jacques Herzog at the ETH Zurich, October 1996. Herzog & de Meuron: Firmitas.

In: Gerhard Mack (ed.). Herzog & de Meuron 1989–1991. Das Gesamtwerk. Band 3 (The Complete Works. Volume 3), Basel / Boston / Berlin, Birkhäuser, 2000, pp. 222–225.

12 Über Tektonik in der Baukunst, Hans Kollhoff, Vieweg & Sohn Verlaggeschellschaft, 1993. A version of his contribution was also published in Oase 47 Bekleding, uitgeverij Sun, ISBN 0169-6238.

13 Petra Brouwer, De wetten van de bouwkunst (The Laws of Architecture), p. 227, Nai Uitgevers, 2011, ISBN 978-90-5662-771-1

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entail a unique sturdiness or firmitas like load-bearing structures.15 The brick-work in the façade is design and beauty, or venustas in the words of Herzog, but at the same time it cannot deny its own structural patterns that derive from the stacking of the bricks. Regarding these patterns, Loos noted in The principal of cladding that ‘each and every material has its own vocabulary of forms and no material can appropriate the forms of another. Forms develop out of the way a particular material is produced and the ways in which it can be worked; they develop with and out of the material’.16 Making a hole for a window or a door in a brick-work surface, the termination of a brickwork façade on the ground level and against the roof, building a corner or a corbel in the façade — these are elements that cannot be treated separately from the formal patterns that arise from the stacking of the bricks. In essence, this is expressed in the headers and course height of the brick used, to which the entire dimensions and proportioning of a brickwork façade can be traced back. In addition, two other matters exert their own structural and construc-tional pattern. First of all, the relative weakness of the prevailing half-brick masonry façade, the maximum height of which is around ten metres, makes it necessary to support the façade at regular intervals. The horizontal and vertical loads of the façade are transferred to the main load-bearing structure of the building through secondary steel structures. These secondary steel structures are also necessary for spanning larger wall openings and parapets. Furthermore, the thermal separation of the main load-bearing structure and the brickwork façade means that the expansion and contraction of the façade — as a result of warming and cooling — differs from the insulated main load-bearing structure, which has a relatively constant temperature. This difference is com-pensated for in practice by providing the brickwork façade with expansion joints, which is actually a form of controlled ‘cracking’. A brickwork façade is not homogeneous as its appearance often suggests, but is actually built up of separate surfaces, each of which leans on the main load-bearing structure. An architect will inevitably have to take these preconditions into account when designing the brickwork façade. As a result of this, the structure and

(massive and filigree construction), whereby the cave coincides with one extreme of the stereotomy, or massive construction, and the tent with the other extreme: the tectonics of filigree construction, in which a clear distinc-tion in material arises between the structure (wooden poles) and the lining (fabric). The hut, made from wood, for example, occupies an intermediate position in which wood continuously switches function and expression between the two standard criteria of structure and cladding. At first sight, the hut appears to be made from one material without distinction between structure and clad-ding. However on closer inspection the hut consists of wooden columns and beams for the structure and thin wooden planks for the cladding. The inter-mediate position of the hut, and the switching of the material between structure and cladding, mirrors the ambivalent character of brick. Placed alongside the recent production of brickwork façades, the question ‘cave, hut or tent?’ is helpful in understanding the way in which the underlying structure ‘shines through’ in the cladding of the building. From the perspective of the ‘middle’ position of the hut, the architects of the projects analysed have explored the possibilities of the expression of the cave and the tent. The image of brick façades ranges from the expression of structure and mass on the one hand, in the works of Herman Zeinstra and Jac. de Brouwer, for example, and the image of a textile cladding on the other hand, in the works of Rudy Uytenhaak and Marlies Rohmer. The positioning among these architects is not dogmatic, they play with various ‘expressions’ within their oeuvre.14 Brick is technically speaking not part of the main construction of a building anymore, but it has not lost its structural role in the metaphorical sense, namely as an expression of the structure. Given its long history, the application of brick forces architects to determine a position on its ambivalent character when designing a façade. However, liberated from its structural yoke, it does raise the question whether brick has become interchangeable with other cladding materials. Can stuc-cowork, for example, be replaced with brickwork in a façade?

THE CONSTRUCTION OF THE CLADDING A brickwork façade is created through the stacking of bricks. In that respect, a brickwork façade does not differ essentially from a brick load-bearing structure. The many possibilities, but also the limitations, in the design of brickwork façades are implied by the very stacking of the bricks. For that reason, brickwork façades have their own structural and constructional patterns; they

Brick Dresses Introduction

14 We asked this question in the interviews. Architects recognise the role of brick as cladding, of course, but they do not take up explicit positions regarding the question of the expression of the underlying structure. They seem to be more interested in the freedom that the material offers for exploring possi-bilities and articulating these. They do not refer to the underlying theoretical discussion and the fun-damental positions.

15 Since 2005, direct practice with building materials has become a part of my teaching to students. I developed these material explorations together with Machiel Spaan in a series of workshops, in particular the workshop Tectonics in Building Culture: Brickwork, as part of the Erasmus Intensive Programme, 2008. In the workshop, walls were developed from the stacking itself by means of ‘dry’ stacking without a prior design. The structural singularity of the stacking was sometimes painfully visible as a result of the walls falling down without there being any external load other than the dead load of the wall itself.

Machiel Spaan and Jan Peter Wingender, Tectonics in Building Culture: Brickwork, 2008. 16 Based on the continuation of his text, Loos would strongly condemn the cladding of a brick structure

with a brick façade, but that is beside the point. Das Princip der Bekleidung, Adolf Loos, Gesammelte Schriften herausgegeben von Adolf Opel, 2010. Lesethek

Verlag, ISBN 973-3-99100-015-0

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The terms ‘filling’ and ‘cladding’ still have a structural basis. The categories ‘decorative’ and ‘imitation of the old’ are based on the design intentions of the architects. Following the classification of Van der Steur, all buildings in the survey fall entirely within the categories ‘cladding’ and ‘decorative’. The last aspect appears, however, to be of a less ‘transitory nature’ than Van der Steur assumed in his text. The façades can be classified according to three parameters: the structural relationship between the brick façade and the main load-bearing structure; the combination of brick with other materials, such as concrete; and, finally, the combination of prefabricated brickwork elements with brickwork made in situ. The survey can be broken up into five categories according to these parameters.19 The first category consists of façades built entirely in situ. This is the most common way of making a brickwork façade. The façades are constructed traditionally, with an inner leaf covered in insulation, an air cavity, and a clad-ding that is executed in half-brick masonry. Steel lintels replace the traditionally elaborated brick elements, such as rowlock courses and arches above windows and doors. Additional secondary steel constructions such as wall supports are placed behind the brickwork in order to transfer the vertical loads in the brick-work façade to the main structure of the building. Due to the difference in thermal movement and the placement of the wall supports, various expansion joints are placed in the brickwork façade. The second group consists of entirely self-supporting brickwork façades. The brickwork is only connected with the main building structure by wall ties that transfer the horizontal (wind) load. By executing the brickwork one brick, or one and half bricks thick, the façade can transfer all vertical loads to the foundations. The secondary steel constructions from the first category can be omitted here. The façade is stronger and better able to absorb its own thermal expansion. However, vertical expansion joints remain necessary in large planes due to the thermal movement of brickwork. In the third form, the brickwork is combined with elements of prefab-ricated concrete. These serve as lintel or wall supports and make the secondary structural facilities visible in the façade. They are often combined with concrete

building techniques will partly determine the design. It is not, therefore, only the why but also the how that determines the ultimate appearance of a façade. In order to make the appearance of a brick building convincing, the architect must ensure both are inextricably linked; the way the structure shines through in the cladding is directly linked to the construction of the cladding itself.

A CLASSIFICATION OF THE PROJECTS The catch-up effort that architects have made in recent years has taken place at the intersection of engineering and architecture, between the technical necessities of keeping a brickwork façade upright and the design intentions of the architects. They perform a balancing act in continually jumping from one leg — the technique, to the other — the design. To limit a survey to the outer ten centimetres of a building, as many publications have done, is insufficient in understanding the balancing act, and the design strategies in brickwork façades arising from it. It would, quite literary, lack depth. One has to dig in deeper to understand the connection between the much discussed expression of the outer brickwork dress and the underlying insulation, secondary steel façade supports and primary main load-bearing structures. On the basis of the archi-tectural and detail drawings delivered by the architects,17 façade fragments from fifteen buildings were drawn afresh for this survey. The layers of the main load-bearing structure, the insulation and the windows, the secondary struc-tural supports, the prefabricated brickwork elements and finally the brick façade itself have been made visible for each building. The positions of the expansion joints and horizontal secondary supports are also drawn in elevation, as a result of which the structure of the brickwork façade becomes visible. The buildings are classified on the basis of common structural charac-teristics. This classification elaborates on the contribution of Van der Steur to the catalogue of the exhibition Nederland bouwt in Baksteen 1800–1940 (The Netherlands Builds with Brick 1800–1940).18 Van der Steur distinguishes between two main directions, namely ‘the pure Dutch development’ and ‘the development under various influences’. ‘Pure development’ is understood to mean the structural use of brick exclusively. The subcategories ‘decorative’, ‘filling material’, ‘cladding material’ and ‘imitation of the old’ are covered under ‘development under influences’. This is actually about the use of brick as cladding in relation to concrete and steel main load-bearing structures.

Brick Dresses Introduction

17 The choice for the examples is partly pragmatic in nature. In order to be able to make the analysis drawings, the construction drawings and details were needed. My thanks go out to all architects who generously made all the drawings and details available, without their trust the analysis would not have been possible.

18 A. van der Steur, De baksteen tusschen 1890–1940 (The Brick Between 1890–1940), Nederland bouwt in Baksteen 1800–1940 (The Netherlands Builds with Brick 1800–1940), Museum Boymans Rotterdam 1941.

19 This classification is helpful in understanding the mutual differences between brick façades, but it should also be noted that projects are sometimes eligible for different categories. When classifying, the determining structural-constructional choices of the architect were considered. For example, brickwork façades with three layers, such as the great courtyard in Ypenburg van Rapp, are in principle self-supporting. However, they were not included in this category because the self-supporting character was not a con-scious design choice, but dictated by the technical standard in the Netherlands. The conscious use of prefabricated lintels is, for example, much more decisive for the design of Rapp. This is in contrast, for example, to the building on the Constantijn Huygenstraat in Amsterdam by Tony Fretton. This includes prefabricated parapets, but these are part of a completely self-supporting façade; the latter was the dominant point of departure in the façade design.

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therefore taken early in the design process. The projects form a new generation of prefabricated brickwork façades whereby, in contrast to the postwar examples, the ‘lightness’ of the cladding is, surprisingly enough, emphasised. The structural analyses and the classification of the projects offer insight into the reciprocal relationship between building and construction techniques and the design of brickwork façades. The answer to the question, ‘Why does a brickwork façade look the way it does?’ is also implicit therein. The design intentions of the architect cannot be seen separately from the way in which the façade is made. From the abstraction of the volume to the expression of the brickwork façade as a textile encasement, from a ‘cave’ to a ‘tent’, in order to arrive at a consistent and convincing image, the architect must incorporate structural and construction technique into the architectural design. This rela-tionship between the design and technique of brick façades will come even more clearly into focus in the coming years as a result of two developments. On the one hand as a result of increasing attention regarding sustainability, and on the other hand, due to the increasing technical possibilities in the production of bricks and the prefabrication of brickwork.

BETWEEN SUPPORT AND CLADDING Since the introduction of the Dutch building law, requirements have been set with regard to energy performance. In 1991, this established a require-ment for a minimum insulation value of Rc 2.5 m2 K/W. Over the years, this requirement has almost doubled to the 2015 requirement of Rc 4.5 m2 K/W. These rising requirements have led to increasingly thicker and technically better insulation materials in recent years. Until now, this has only influenced the distance between the inner leaf and the brick outer leaf of a cavity structure and, therefore, on the transfer of wind load by means of the wall ties. However, a break-even point is approaching. With the increasing perfection of the insu-lation, interruptions in it will determine the ultimate performance of the entire façade. Isokorbs for anchoring balconies and galleries, and the secondary steel structures supporting brickwork façades, will begin to form the thermal weak points of the façade. In Swiss building practice, the use of such interrup-tions has already become practically impossible with the MinErgie / EcoPlus standard. The question also increasingly arises whether steel structures with a limited lifespan are desirable in a brick façade with an inherently much longer lifespan. The ultimate sustainability of a façade is, indeed, determined by the weakest link. Under pressure to make façades more sustainable, the usual ‘traditional’ solutions using secondary steel structures to keep the brick dress upright will eventually become impossible. The practical ‘solution’ of directly gluing 3cm-thick brick strips on insulation materials are already being adhered

elements that fulfil no structural role, but which arise from the design of the façade. The combination of brick and concrete harks back to the use of natural stone elements in brick buildings. Elements such as lintels, sills, weather cor-nices, string courses, plinths and reveals of doors were often executed in natural stone for technical, practical and aesthetic reasons. The combination of brick-work and concrete was also a separate category for Van der Steur. Brick was seen as a ‘filling’ element of a concrete main load-bearing structure. Insulation and thermal breaks did not yet play a role in that. This combination developed into concrete elements that fulfil a secondary structural function in the façade. The technical construction of the façade does not actually differ from a tradi-tional brickwork façade. The limited structural possibilities of half-brick façades and the need for expansion joints in the façade continue to exist. In the fourth category, there are prefabricated brickwork elements, mostly lintels and wall supporting string courses, combined with brickwork made in situ. This combination is frequently applied in practice. The prefab-ricated elements consist of concrete elements into which whole bricks are embedded, or onto which brick slips are glued. The Dutch practice of pointing the brickwork joints creates an almost invisible transition between prefabri-cated elements and brickwork made in situ. In the case of a maximum of three stories, the prefabricated elements have a structural role as lintels above the openings. With higher buildings, a secondary façade support is necessary every two stories. In this case, the prefabricated concrete parts are connected to the main load-bearing structure of the building, as a result of which a sep-arate secondary structure with steel wall supports is unnecessary. From the viewpoint of the design, a motive for this form of prefabrication is the homo-geneity of the appearance. For example, one can avoid visible steel profiles above the window openings. The construction of special brickwork patterns, such as vertical brickwork, is labour intensive. Therefore the application of prefabricated elements with these patterns is also beneficial for the speed of construction and the costs involved. In the last category, the brick façade consists entirely of prefabricated elements. In the façades, the brickwork is ‘mounted’ and no longer constructed in situ. The prefabrication of façade-filling brick elements was mainly developed in the postwar residential building production in the Netherlands. The building method with ‘heavy’ façade-filling elements was especially interesting from an economic and production perspective. Although this building method fit well in the modern idea of industrialisation, architects in the postwar years were unable to come up with an architectural design answer to this application. When opting for prefabrication, design and construction techniques are intertwined in a far-reaching way in recent examples. The decision for prefabrication is

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façades emphasise the textile qualities of brick as a cladding material. The previously mentioned inclination for decoration and the use of patterns among architects and the greater public will only further reinforce this development. A next, spectacular step in this direction is visible in the research and work of the Swiss architects Gramazio & Kohler at the ETH Zürich.21 As a result of the efforts of a robot that stacks bricks on the basis of given coordinates, it is possible to develop patterns in brickwork that avoid the traditional brickwork bonds. The bond is necessary when processing bricks by hand, because it determines exactly where the mason will place the following brick. Without a bond, the mason is helpless in a certain sense. By stacking with the robot, this need disappears and seamless patterns are possible. The traditional rep-etition of stack-patterns in brickwork is making way for a façade-filling pattern without repetition. Graphic images are finding their way into brickwork façades that are comparable, for example, to paintings on a stuccoed façade.

THE ELEGANCE OF A BRICK DRESS New buildings have to acquire a position in the history and development of a place. Brick is being assigned a mediating role in this by many Dutch archi-tects. It connects the new to the existing in the city by means of the continuity of the material. Herein, to a certain extent, lies the significance of brick as a cladding material. The examples in this book demonstrate, above all, that this connection, within the restrictions that the material entails, offers archi-tects the freedom to develop a personal and perceptible signature in the design of the façade without causing alienation from the environment. The brick dresses mediate, just like pieces of clothing, between the expression of the individual — both the building as well as the architect — and the conventions of the environment. The limitations of the material, but also the possibilities that emerge due to the developments in the field of sustainability and prefabrication, make it clear that when architects design their brickwork façades, they must deter-mine a position again and again at the interface of engineering, construction and design. ‘Design by the thinking of the making’ as the Smithsons pointed out. That is not new. It is a constant, if not the basis, in the development of architecture. It points to the collective domain of our field. All architects wrestle with the same problem. That collective wrestling offers a counterbalance for the Superdutch image of architecture as merely an expression of individual concepts and artistic ambitions. The materials used and the manner in which buildings are constructed determine to a substantial degree how they will look.

to in practice. Viewed with suspicion by many architects, this development fundamentally questions the role of brick. As a result of the gluing, the inherent logic of stacking as the foundation for a brick structure, both technically and architecturally, has become obsolete. The trusted image from which brick derives its significance is disappearing definitively. ‘Anything goes’, just as with tiles. So why would we still act as if it were brickwork? Another objection to this development concerns the sturdiness of the façade, because this is determined by the insulation materials and not by the bricks. Many architects also doubt if glued brick strips will remain intact over time: a brick façade with dents is a nightmarish vision. An alternative solution could gain significance: the self-supporting façades that are described in the second category. These have no secondary structures and are thermally detached from the main load-bearing structure, which would create a high performance insulation without interruptions. This is possible, in principle, with a half-brick façade in buildings up to three floors, as is customary in Dutch building practice. Higher buildings require a thicker brickwork façade, and this, in turn, offers the potential to support galleries and balconies, as a result of which isokorb connections, for example, would be prevented. The extra investment is repaid in energy-saving, but also in practical sustainability. It delivers sturdy façades that withstand time well. From this perspective, the projects discussed here by Herman Zeinstra and Tony Fretton can be seen as possible precursors to a new development in Dutch architecture. Since the 1980s, brick factories have invested in further perfecting tech-niques for producing brick. Specific project productions and specially shaped bricks and sizes are increasingly often the standard. This development also follows on from the recent desire for ornamentation and decoration in archi-tecture. As a result of the use of specially shaped bricks, decorative patterns and the accenting of special elements of a building, such as in an entrance, are perfectly possible. The distinction between coarse and fine ceramics is blurring, and the market is changing from supply to demand driven produc-tions.20 There seems to be no end in sight, for the time being, to the prolifer-ation of possibilities that are forcing architects to choose, and therefore to further articulate a design. The processing of brick in prefabricated elements is also growing enormously. The examples of Heren 5 and Rudy Uytenhaak demonstrate the transition from traditional, heavy façade-filling prefabricated elements to a light filigree use of prefabricated brickwork. These prefabricated

Brick Dresses Introduction

20 For a more extensive analysis of this, see also Louise Schouwenberg, De stad vertelt verhalen: Over technische innovatie in de baksteenindustrie en het veranderende beeld van de stad (‘The City Tells Stories: technological innovation in the brick industry and the changing image of the city’). Included in this publication. 21 For the research by Gramazio & Kohler, see also www.dfab.arch.ethz.ch

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Brick Dresses

In the projects presented, architects connect the design of brickwork façades to the constructional engineering preconditions that are dictated by the choice of material: architecture and engineering become inextricably linked in these inspiring examples. Again and again, architects seek out the precarious balance between structural consistency on the one hand, and the consistency of the sought-after architectural image on the other. That precarious balance between technique and design, which the proj-ects bear witness to, is recognisable to the observer and alludes to the concept of elegance.22 This is not elegance in the fashionable sense, although it is tempting to consider that in relation to a brick dress. It has more to do with the elegance that the mathematician Henri Poincaré saw in a mathematical demonstration.

‘Es ist die Harmonie der verschiedenen Teile, ihre Symmetrie, ihr schönes Gleichgewicht; in einem Wort: alles, was Ordnung schafft, was uns erlaubt, die Dinge klar zu sehen und sowohl das Ganze wie auch zu gleicher Zeit die Details zu überblicken… Kurz, das Gefühl der mathematischen Eleganz ist nichts anderes als die Befriedigung, welche uns eine gewisse Übereinstim-mung zwischen der gefunden Lösung und den Bedürfnissen des Geistes bietet, und auf Grund dieser Übereinstimmung kann uns die Lösung als neues Werkzeug dienen.’ 23

An elegance that arises at the moment when technique and design can no longer be distinguished from each other; when the solution to a technical problem — such as a banal expansion joint — and the overall design of the façade coincide. Elegance, in the words of Poincaré, is also a balance that liberates the needs of the mind. Not those of the architect, but those of the observer. The image only convinces when the arrangement of a brickwork façade can be understood from the greater whole to the smallest detail. And, following on from the idea of Poincaré, that the solutions which underlie this satisfying, elegant balance form the collective basis in order to be able to take the next step in the aforementioned development of brickwork. The ongoing devel-opment of brick as a cladding material allows us to take up a position again and again between the firmitas and venustas of the façade. Finding a convincing image for brickwork, as the cladding of the structure, which simultaneously gives expression to the structure of the cladding itself.

22 For an analysis of the concept of elegance, I would like to refer to Phillip Esch’s article, Die Überein-stimmung von Form und Inhalt, Werk, Bauen + Wohnen 5, 2010.

23 Henri Poincaré, Wissenschaft und Methode, Leipzig, 1914.

1.1 CENAKEL TOWERS 2221.2 LANGERAK, FIELD 6 AND 11 2261.3 IJBURG BLOK 56 2301.4 FUSION MOSQUE 234

Brick. An Exacting Material

STANDARD BRICKWORK FAÇADES

Jan Peter Wingender

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