Engineering Elegance

Patrik Schumacher, London 2007
Published in: Hanif Kara (editor), Design Engineering AKT, London 2008

Elegance has been promoted as a new watchword to guide the next step within the current cycle of architectural innovation.1
The elegance we mean is not the elegance of minimalism. Minimalist elegance thrives on simplicity. The elegance I am promoting here thrives on complexity. It relies on powerful ordering principles that can establish lawful and legible continuities within a given manifold. Elegance in our terms achieves a reduction of visual complexity, thereby preserving an underlying organizational complexity. In short: Elegance articulates complexity. This is my fundamental thesis, and I would like to argue here that a congenial structural engineering approach is absolutely central to this ambition.

Attributed to a person elegance suggests the effortless display of sophistication. We also talk about an elegant solution to a complex problem. In fact only if the problem is complex and difficult does the solution deserve the attribute “elegant”. While simplistic solutions are pseudo-solutions, the elegant solution is marked by an economy of means by which it conquers complexity and resolves complications.
It is this kind of connotation that I would like to harness for a contemporary notion of elegance in architecture and engineering. An elegant building should entail an elegant structure and both together should be able to spatialize considerable organisational complexity without descending into visual disorder.

It is the sense of law-governed complexity that assimilates this work to the forms and spaces we perceive in natural systems, where all forms are the result of lawfully interacting forces. Just like natural systems, elegant compositions are so highly integrated that they cannot be easily decomposed into independent subsystems – a major point of difference in comparison with the modern design paradigm of clear separation of functional subsystems. In fact the exploitation of natural forms like landscape formations or organic morphologies as a source domain for analogical transference into architecture makes a constructive contribution to the development of this new paradigm and language of architecture.
Structural engineering had its own significant share of inspiration from nature. Frei Otto went a step further and literally harnessed the lawfulness of physical systems as form-finding procedure to generate his design-morphology. The results have been striking. These processes might be referred to as “material computing”2. Such analog form-finding processes can complement the new digital design tools that might in fact be described as quasi-physical form-finding processes.
Elegant compositions or complexes are highly integrated formal/spatial systems that look like those highly integrated natural systems where all forms are the result of the lawful interaction of physical forces or like organic system where the forms result from a similar play of forces selected and integrated in adaptation to performance requirements. Such elegant compositions resist decomposition, just like their natural models.

Computing Elegance – The Digital Revolution in Architecture and Engineering

Current digital modeling tools are able to facilitate integrative effects: lofting, spline-networks, soft-bodies, force-fields etc. Morphing – the ultimate effect of animation movie technology -  has been an often emulated paradigm for achieving the continuity of the differentiated.
There is an inevitable, powerful relationship between the new digital tools on the one hand and the new organizational patterns, compositional tropes, stylistic characteristics and aesthetic values on the other hand. At Zaha Hadid Architects we are currently promoting the slogan: Total Fluidity across all Scales.3 In fact it has become increasingly easy to achieve abstract sketch-designs (surfaces) that satisfy this slogan and thereby achieve a measure of elegance as defined here. However, pure geometry (surface) models are only the first sketchy step in the design of an elegant architecture. Only in limit cases such as the installation “ice-storm”4  -  an extensive experiment in morphing -  does the modeled surface translate directly into a built reality. (The whole environment was executed as a CNC-milled poly-styrene body with a hardened poly-urethane skin.)
It is quite a different challenge to maintain a high degree of fluidity and coherence with respect to the design of a fully functional building where multiple functional and technical requirements impose the handling of multiple material sub-systems: the (multi-layered) envelope system, the system of internal spatial divisions, the system of circulation/navigation, the various service systems, and the structural system. The necessity of distinct subsystems poses the crucial task of organic inter-articulation as the battle-field where elegance is won or lost. The structural system often plays a domineering role in this concert of subsystem. Organic inter-articulation might be achieved by mutual geometric affiliation, inflection or by means of establishing lawful correlations between the various patterns of differentiation that are specific to each subsystem. The contemporary desire for smooth transitions and gradient transformations between conditions might be correlated with gradient structural modulations that translate the continuously differentiated distribution of forces that operate in any structural system.

Structural Fluidity

The digital revolution that brought a series of powerful new design tools into architecture has also provided structural engineering with new tools to analyse and calculate structures in the manner that is congenial to the architectural ambitions towards total fluidity that have been unleashed by the new design tools.  Traditional architecture was a game of assembling simple platonic forms like cubes, planes, grids, domes, and pyramids. The key characteristic of contemporary architecture that challenges engineering is the pursuit of complex three-dimensional geometry and continuously changing forms. Such forms can no longer be analysed by means of decomposing them into discreet systems. This is significant because it challenges structural engineering with respect to its most basic concepts.
Traditional structural engineering relies on the ability to decompose any structure into clear and independent structural sub-systems. Each sub-system adheres to standard concepts like column, beam, portal frame, arch, slab, vault, framework etc.  Each of these concepts is characterised by a clearly typified geometric schema with its attendant distribution of forces. Within each simple subsystem the active forces can be easily ascertained, and great care is taken to control the transference of forces from subsystem to subsystem by the precise articulation of the joints.  The overall arrangement of forces can then be traced step by step. This strategy of clear and distinct decomposition sacrifices efficiency and redundancy for analytical clarity and tractability. It is a strategy for the reduction of complexity that recognises the narrow computational capacity of the pre-digital era. In contrast contemporary architecture creates spaces which are morphing different spatial sections into a seamlessly differentiated continuum that resists such decomposition. In all these traditional systems the ability to analyse and calculate the behaviour of the structure is premised upon the purity of structural type and the severing of all redundant connections.
It is precisely the underlying typology – the thinking in clearly defined types – that is disappearing from contemporary architecture.  In fact, “From Typology to Topology” is one of the key slogans of contemporary architecture. This implies that contemporary architecture escapes all traditional engineering procedures. Within a contemporary avant-garde building like the Phaeno Science Museum in Wolfsburg5, the structural systems morph as much as the architectural forms.
With new engineering tools like finite element analysis, which break the structures into particles rather than into parts, the engineer is able to capture the ever shifting arrangement of forces. The universe of potential force patterns becomes boundless.
 “From Parts to Particles” is another key slogan of contemporary architecture.
Structural engineers can now analyse mixed, hybrid systems. A tool like Finite Element Analysis can also cope with dense, redundant interrelations of the parts of a structure. We no longer need to sever and isolate the structural components or subsystems.  This means that we can harness the structural efficiency of an interconnected network, where parts work together rather than remaining independent from each other.  The re-tooled engineer allows the structural forces to flow freely through the surfaces provided by the architect. This is the era of structural fluidity.
In the case of the Phaeno Science Museum (to be described below) we can observe a mixture of spanning, cantilevering and vaulting within a waffle slab whereby spans and cantilevering dimensions are continuously changing. The cones flare into waffle-slab rather than remaining discreet props that pick up their load at distinct points of contact. The space frame above is continuously differentiated whereby each member within the space frame has a different angle (the grid fans in two directions) so that each cell of the space frame has a different size.  In a complimentary move each member has a different thickness and weight.  Obviously, this nuanced optimisation can only be coped with by means of computers, both with respect to the calculation of forces as well as with respect to the handling of the geometry and manufacturing schedules.

Emergent Perfection

The notion of elegance promoted here still gives a certain relevance to Alberti’s criterion of beauty: you can neither add, nor subtract without destroying the harmony achieved. Except in the case of contemporary elegance the overall composition lacks this sense of perfect closure that is implied in Alberti’s conception. Alberti focused on key ordering principles, like symmetry and proportion. These principles were seen as integrating the various parts into a whole by means of setting those parts into definite relations of relative position and proportion in analogy to the human figure. Perhaps the best example of this ideal is the Palladian villa. In contrast contemporary projects remain incomplete compositions, more akin to the Deleuzian notion of assemblage than to the classical conception of the organism. Our current idea of organic integration does not rely on fixed ideal types. Neither does it presuppose any proportional system, nor does it privilege symmetry. Instead the parts or subsystems mutually inflect and adapt to each other achieving integration by various modes of spatial interlocking, soft transitions at the boundaries between parts, morphological affiliation, and lawful correlation between parallel patterns of differentiation etc.
Naturally, on the way to the elaboration of fully functional, fully detailed designs, whereby evermore systems or layers need to be integrated, the principle of inflection (organic inter-articulation) becomes evermore difficult to maintain. Also the visual field is in danger of being overcrowded, compromising legibility and orientation.
It is at this moment of mounting difficulty  - in the face of bringing the new paradigm into large scale realization -  that elegance becomes an explicit priority, not least because the built results have all too often been disappointing in this respect.

The principle of elegance postulates: do not add or subtract without elaborate inflections, mediations or interarticulations.
While the classical concept of preordained perfection has thus been abandoned, there still remains a strong sense of increasing tightness and stringency, approaching even a sense of internal necessity, as the network of compositional relations is elaborated and tightened. This network of “compositional” relations includes the arrangement and morphology of the structure.6 I guess every designer knows this from his/her own design experience. The more the compositional cross-referencing, inflection and organic inter-articulation within the design has been advanced, the harder it becomes to add or subtract elements. This kind of design trajectory  - although wide open at the beginning -  beyond a certain point becomes heavily self-constraining. One might be inclined to talk about the increasing self-determination of a composition: an emergent (rather than preordained) perfection.
I guess every designer knows how a design-trajectory can lead into a dead end, can fail to “work”, or remain unresolved. The elegance we mean  - elegance on top of complexity -  is a tall order, and can not be secured in advance.
With increasing complexity the maintenance of elegance becomes increasingly demanding.
Complexity and elegance stand in a relation of precarious mutual amplification: a relation of increasingly impropable mutual enhancement, i.e. mutual amplification with increasing probability of failure.
The recently completed Science Museum in Wolfsburg (“Phaeno”) is the virtuoso masterpiece in the articulation of complex continuities that can be followed all the way through the building. The whole building is inscribed within a rigid trapezoid whose angles are adapted to the site-condition. Within this sharp-edged trapezoid everything flows and melds without corners. The ground-surface is molded into an artificial topography that registers and receives the cones that carry the building. These cones – executed in insitu reinforced concrete -  constitute the primary structure of the building. Each cone has its own variation of angles and radii. The cones blend seamlessly into the waffle-slab above. Some of those cones also reemerge within the interior – either as craters or as cones that continue to carry the space-frame above. There is an essential symbiosis in the spatial and structural conception of the building, and a close inter-articulation of the waffle concrete structure of the raised floor and the steel space-frame that carries the roof. To a large extent the architectural expression is dominated by the structure. In fact, the structure constitutes the architecture, and therefore the demand for tight collaboration was extraordinary.
The lateral openings are of two kinds: the large openings are conic sections that produce the characteristic parabula form, and the smaller openings come in swarms that are articulated as variations of the swarm of voids that make up the waffle slab. In both cases the openings closely relate to the respective structural logic of the surfaces penetrated. These openings in turn contribute and relate to the rhythmic flow of the interior spaces. The large, continuous  expanse of space on the interior is captured between the crater-scape produced by the cones pushing through the floorslab and the continuous space-frame. These two layers are correlated via mutually echoing shifts in section. It is this resonance between the various layers and sub-systems that gives this space its exhilarating sense of complex order that we perceive as elegance. The fact that this stimulating spatial experience is delivered by the structure itself rather that by some less substantial and more lightweight layer adds enormously to the power of the effect.

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