Parametrics Explained

Contemporary digital design practice is in a state of rapid evolution. While architects have employed

computer-aided drafting (CAD) systems for decades, only recently have two distinct and potent design

sensibilities - parametric and algorithmic design - emerged. Nurtured by early architectural researchers and

programmers operating in practice, these methodologies are now gaining widespread professional and

academic acceptance.

Together these two techniques are opening up a new field of possibilities for architectural practice. Most

significantly, they have been developed and refined primarily in commercial practice and not in academia.

Since the late 90s, these advances have coincided with the emergence of a number of digital research

units within commercial practice, such as the Specialist Modelling Group at Foster and Partners, Gehry

Technologies spun off of Gehry Partners, the Advanced Geometry Unit at Arup, and CODE at Zaha Hadid

Architects. These in-house digital research units have been developed as a means of ensuring that the

complex buildings of today are designed and constructed efficiently, on time and within budget. We can

therefore discern an evolution within the development of digital design tools, from a period when they were

associated with science fiction and virtual reality in the 1990s, through to a period when they began to be

used to understand within the realm of digital tectonics to understand material behaviors in the 2000s,

through to a moment when they have become almost indispensable in the production of complex buildings

in the 2010s.

However, these two design sensibilities – parametric and algorithmic design - are often confused, and

sometimes collapsed into the single term, ‘parametricism’. This article is an attempt to clarify the situation,

and to offer some precise definitions of terms in order to differentiate these two quite distinct digital

techniques. It is also an attempt to evaluate the term ‘parametricism’ itself, and to question whether or not

what we see emerging is a new ‘style’ of architecture [1].

Parametric Design

Parametric is a term used in a variety of disciplines from mathematics through to design. Literally it means

working within parameters of a defined range. Within the specific field of contemporary design, however, it

refers broadly to the utilization of parametric modeling software. In contrast to standard software packages

based on datum geometric objects, parametric software links dimensions and parameters to geometry

thereby allowing for the incremental adjustment of a part which then affects the whole assembly. For

example, as a point within a curve is repositioned the whole curve comes to realign itself. The operations

that it facilitates are adaptation, blending and smoothing. It is therefore useful not only in modeling

individual forms but also in the whole field of associative urban planning.

Parametric software lends itself to curvilinear design, as in the work of Frank Gehry, Zaha Hadid, and

other architects whose work is characterized by the manipulation of form. In itself, however, parametric

software does not open up a new vocabulary of form. Such offices were modeling using analog techniques

long before the introduction of parametric software. However, these techniques are highly efficient

for remodeling forms, and afford greater control in the design process. They also provide more precise

information for digital fabrication processes.

It would be wrong, however, to assume that parametric design is concerned solely with form-making. On

the contrary, parametric techniques afford the architect with new modes of efficiency compared to standard

approaches and new ways of coordinating the construction process (called Building Information Modelling),

as in the case of Digital Project, an architectural version of CATIA customized for the building industry

by Gehry Technologies. The big advantage of such packages is that they allow the construction team to

interface on a single platform, and afford a higher level of control in terms of monitoring the time and cost of

construction.

Algorithmic Design

Algorithmic is a term that refers to the use of procedural techniques in solving design problems. Technically

an algorithm is a simple instruction. It therefore relates as much to standard analog design processes, as

it does to digital design processes. Within the field of digital design, however, it refers specifically to the

use of scripting languages that allow the designer to step beyond the limitations of the user interface, and

to design through the direct manipulation not of form but of code. Typically algorithmic design would be

performed through computer programming languages like RhinoScript, MEL (Maya Embedded Language),

Visual Basic, or 3dMaxScript. In contrast, due to the difficulty of programming, the applications Generative

Components and Grasshopper bypass code with pictographic forms of automation. We might therefore

describe them as forms of graphic scripting. Algorithmic design exploits the capacity of the computer to

operate as a search engine, and perform tasks that would otherwise consume inordinate time. It therefore

lends itself to optimization and other tasks beyond the limitations of standard design constraints [2].

Parametric versus Algorithmic

There is now a widespread practice of conflation the two terms, ‘parametric’ and ‘algorithmic’. This is

partly due to the fact that the two techniques can end up producing similar forms. Algorithmic work

generated using Processing or Rhino script, for example, often has curvilinear forms that are seemingly

similar to work produced using parametric tools. But it is also partly due to the fact that as yet there is little

real understanding of what the terms actually mean – at least on the part of those less familiar with the

world of computation. To some extent the term, ‘parametric’, has become a short hand way of bracketing

much digital design that seems to be curvilinear in its aesthetic expression, thereby providing a convenient

expression for a new style in architecture.

Although there will always be a need for synonyms or accessible terms to describe broad approaches, this

development is a little disturbing, and will lead no doubt to further confusion. Often within architectural

culture terms have been adopted that have little relevance to their use in culture at large. Indeed we can

look through the history of architecture, and find several terms, such as ‘Postmodernism’ or ‘Deconstructivism/

Deconstruction’, adopted within an architectural context to refer to architectural styles in a way that has

made them reduced parodies of their original cultural meanings [3]. Parametrics or parametric design

now seems to be suffering a similar fate: although it is actually a new digital technique that fosters a new

process or methodology of design, it has now been adopted to refer to a new aesthetic expression or style

of architecture.

As computation becomes increasingly prevalent within architectural culture, some effort must therefore be

made to clarify the terms, before the confusion becomes so widespread that the use of the term parametric

to describe a style is sanctioned through sheer popularity. So let us state here quite clearly: algorithmic

techniques are based on the use of code. Parametric techniques are based on the manipulation of form.

They are therefore quite distinct techniques.

At the same time algorithmic techniques are often used in association with parametric techniques. We

might point, for example, to the use of certain algorithmic techniques to generate the initial form that is

subsequently manipulated using parametric techniques. Conversely, algorithmic techniques can be used for

optimization and other operations at the other end of the design process, once the initial generated form has

been modeled through parametric techniques.

There is, however, a deeper concern that destabilizes this neat distinction between the parametric and the

algorithmic, and this is the role of visualization in the process of design. Many architects do not learn to

write code from scratch, but learn by ‘hacking into’ the logic of the code displayed in boxes on the screen, as

they model forms using platforms such as Maya or Rhino. In other words, the code is used merely to provide

the ‘key’ to the manipulation of form, and can be understood primarily through the medium of the visual.

This emphasis on the visual is heightened further with the introduction of recent applications - such as

Grasshopper - that bypass code by using pictographic forms of automation. In the end it is not so clear how

many architects are working within a truly algorithmic framework, as opposed to simply operating within a

visual framework.

Further, it could be argued that parametric and algorithmic operations share certain similarities, in that

both are containers in which values can change based on user input. Just as one can adjust the code

algorithmically to generate different outcomes, so one can adjust the form parametrically to generate

different outcomes. Both operations appear to be based on the adjustment of parameters. Indeed the

introduction of graphic scripting techniques, such as Grasshopper, serves only to blur the distinction

between parametric and algorithmic design. Moreover all parametric design relies necessarily on code. In

other words we find ourselves in a dialectical situation where code and form rely upon one another. There

can be no form without code, and often no code without form. To some extent, then, algorithmic design and

parametric design are merely two sides of the same coin.

Yet there are clear distinctions that can and must be made between the algorithmic and parametric design.

Importantly, it is the duration and permanency of their connections to parameters that distinguish them

as operations. Further, parametric design depends greatly on a manipulation of form that might appear

visually interesting, but is often superficial. The blend-shape modeling operation, for example, can be used

to smooth out form in a seductive visual way – especially at an urban level - but cannot take account of any

useful performance related information embedded in a Building Information Modeling (BIM) model.

Moreover, a distinction should made between graphic scripting techniques, such as Grasshopper, and nonpictorial

forms of scripting. Graphic scripting is relatively limited in its scope. Seldom are there any code trees

to be found in Grasshopper robust enough to compete with the average text based scripting. Indeed graphic

codes have no text editor, and have severe limitations in terms of accuracy, constructability, rationalization

and scalability. Code based scripting enjoys far greater levels of control. Despite their apparent similarities,

then, there are important distinctions to be made not only between algorithmic and parametric operations,

but also between visual scripting and purely code-based algorithmic operations.

Parametricism

The popularity of these new techniques has spawned a new term, ‘Parametricism’. Patrik Schumacher,

a partner in Zaha Hadid Architects and a founding director of the Design Research Laboratory at the

Architectural Association in London, has argued that the term should be adopted for a new ‘style’ of

architecture. In his bold claim he highlights the prevalence of parametric design today, a prevalence that is

underpinned, he maintains, by the popularity of recently developed parametric modeling techniques.

Schumacher begins his article, ‘Parametricism: A New Global Style for Architecture and Urban Design’, by

claiming that parametricism is the new global style for architecture: ‘There is a global convergence in recent

avant-garde architecture that justifies its designation as a new style: parametricism. It is a style rooted in

digital animation techniques, its latest refinements based on advanced parametric design systems and

scripting methods [4].

For Schumacher, moreover, it is a style that has succeeded Modernism as the new global style: ‘Developed

over the past 15 years and now claiming hegemony within avant-garde architecture practice, it succeeds

Modernism as the next long wave of systematic innovation. Parametricism finally brings to an end the

transitional phase of uncertainty engendered by the crisis of Modernism and marked by a series of relatively

short-lived architectural episodes that included Postmodernism, Deconstructivism and Minimalism. So

pervasive is the application of its techniques that parametricism is now evidenced at all scales from

architecture to interior design to large urban design. Indeed, the larger the project, the more pronounced is

parametricism’s superior capacity to articulate programmatic complexity [5].

Interestingly, although Schumacher is careful to distinguish parametric techniques from scripting techniques,

he nonetheless brackets them together as part of a bigger movement that he calls ‘Parametricism’.

In other words, although he does not make the mistake of conflating the two, he invents a new term,

‘Parametricism’, that is defined in such a way that it embraces both techniques. According to Schumacher,

then, Parametricism is not limited to the parametric.

What is perhaps more problematic, however, is the way in which Schumacher defines the parametric itself.

Schumacher speaks about it as though it has become some dominant mode of operation. Were we to chart,

however, the various modes of designing in the contemporary academic environment, we would probably

find the use of genuine parametric softwares, such as Digital Project, to be fairly marginal. The vast majority

might be using explicit modeling techniques, such as Maya or 3D Rhino, and a relative minority would be using

graphic/coded automation of some form, but only a very small fraction – maybe 1% - would be using actual

parametric software. Certainly within Schumacher’s own office – Zaha Hadid Architects – Digital Project is

used extensively, but seldom as a design tool. Indeed its role is largely to control the logistics of construction.

What becomes clear – and this is surely the weakest part of the argument – is that Schumacher seems to

want to appropriate the whole pre-parametric legacy of NURBS and SUB-D geometry rule-sets within his

vocabulary of ‘Parametricism’. By doing this, within the scope of ‘Parametricism’ he effectively lays claim to

all curvilinear forms, whether or not they are generated parametrically. Furthermore, although Schumacher

cites Frei Otto’s form-finding experiments, and even claims that Otto ‘might be considered as the sole true

precursor of Parametricism’, he shows little evidence of actual form-finding techniques in his own work [6]. It

begins to emerge that Schumacher is arguing largely not only for style rather than design methodology, but

also for form rather than form-finding.

This brings us to perhaps the most controversial claim made by Schumacher – that Parametricism is a

new ‘style’ for architecture and urban design. Although this ‘style’ is ‘rooted in’ certain techniques including

parametric techniques and scripting, it cannot be reduced to those techniques. ‘What confronts us,’ notes

Schumacher, ‘is a new style rather than merely a new set of techniques.’ [7] He argues that the techniques

themselves have inspired ‘a new collective movement with radically new ambitions and values’. This in

turn has led to ‘many new, systematically connected design problems that are worked on competitively by

a global network of design researchers’. This leads Schumacher to conclude, ‘Over and above aesthetic

recognisability, it is this pervasive, long-term consistency of shared design ambitions/problems that justifies

the enunciation of a new style in the sense of an epochal phenomenon.’ [8]

Schumacher is correct to use the term ‘style’, even though it has become a somewhat controversial term.

Schumacher would no doubt argue that ‘style’ is being used here in a very different sense to the typical

Postmodern treatment of it as mere representation or appearance. Style here comes to mean ‘effect’ and

should be understood within a deeper historical framework that stretches back to Gottfried Semper and

beyond, where outward appearance is understood as the ‘effect’ of certain underlying processes. Whatever

the techniques used in generating any form, we certainly need to address the question of the resultant

appearance or representation. Moreover, despite the fashionable contemporary interest in process, we

simply cannot escape representation. It is not simply that within a Deleuzian framework ‘process’ and

‘representation’ should be understood as locked within a mechanism of reciprocal presupposition, in that

process feeds into – and deterritorializes – representation, no less than representation feeds into – and

deterritorializes - process. Rather we should understand representation as a direct ‘effect’ of material

concerns that govern the design process [9]. We can never escape style.

Schumacher is also correct no doubt in implying that techniques themselves are always grounded in

a cultural context – with new ‘ambitions and values’. Techniques can facilitate or even ‘invite’ certain

operations, simply because they make it easier to perform them. Just as in the past the adoption of the

parallel motion on drawing boards encouraged the use of parallel straight lines in the design process, so

too today the adoption of parametric software in the computers encourages the use of curvilinear forms.

However, there is nothing in techniques themselves that ensures the selection of such forms. Techniques

themselves are neutral. Rather, as Schumacher observes, it is culture itself that engenders a certain design

aesthetic, and the techniques can merely facilitate the articulation of that aesthetic. Of course, the system

can also work in reverse, in that the sheer demand for a certain aesthetic can encourage the development

of certain software tools – as happened with the customization of CATIA to produce Digital Project. But

techniques themselves are not responsible for generating a design aesthetic.

Finally, Schumacher is also clearly correct in detecting certain common tendencies within design practices

around the world. It is clear that the use of similar tools and techniques is likely to promote an increasingly

homogenized design culture, a tendency that will be exacerbated by the globalization of culture in general,

along with the growing internationalization of architectural practice and education. Just as architectural

practitioners, such as Zaha Hadid or Rem Koolhaas, are designing buildings all over the world, so too

architectural professors, such as Greg Lynn or Roland Snooks, are teaching in multiple schools of architecture

in different continents at the same time. Likewise through the internet and global publications – such as

this catalog - architectural ideas are being disseminated more and more effectively. It is easy to understand

therefore how a new design aesthetic might be spreading across the globe.

Where Schumacher needs to be challenged, however, is in his use of the term, ‘Parametricism’ to describe

this new design aesthetic. Not only is the work described largely not parametric in that it has not been

generated using parametric tools, but also it has its origins in a pre-computational world. Furthermore, it

seems somewhat perverse, given that Schumacher expresses clearly that what he is describing ‘is a new

style rather than merely a new set of techniques’, that he adopts a term, ‘Parametricism’, that is clearly

derived etymologically from a particular technique. We therefore find ourselves in a somewhat confusing

situation where a relatively marginal computational technique has been co-opted to refer to a whole new

style of architecture.

A New Global Style?

Modernist discourse tends to see the world in terms of universals. By contrast postmodern discourse tends

to present the world in terms of multiplicities. As the ‘grand narratives’ of modernity give way to the minor

narratives of Postmodernity, we can detect a shift from universals to multiplicities, from homogenization to

differentiation [10]. We now live in a world of differences, where the belief in universal truths or universals

of any kind has been called into question. As such, the notion that a new universal style has now usurped

Modernism comes across as paradoxically Modernist.

Yet my real concern is that Schumacher’s position is not Modernist, but Postmodernist, as the very

differentiation of Postmodern culture is also highly problematic. As Fredric Jameson has argued – in the

context of the call for Regionalism within architecture – the urge to counter the homogenization of late

capitalism by celebrating ‘difference’ is itself complicit within the logic of late capitalism itself [11]. Difference,

as Jameson notes, becomes another commodity within the marketplace. Rather then overcoming the

homogenizing tendencies of late capitalism, it can therefore be seen to be feeding them.

By extension, it could be argued that other attempts to resist the global – such as anti-globalization – fall

within the logic of globalization, just as attempts to resist brand-name culture, such as the Japanese nobrand-

name store, Muji, fall ultimately within the brand-name logic. Of course, such a subtly dialectical

argument can work the other way. The more universal things become, the more we notice the differences

between them. The universal tower block, for example, is treated very differently across the globe. While

in Eastern Europe it is often derided as an emblem of Soviet Bloc totalitarianism, in China is celebrated as

the emblem of the new China. The global and the local, it would appear, are not distinct categories, but are

locked into a logic of reciprocal presupposition. The global promotes the local, just as the local promotes the

global. It is not surprising, then, that the hybrid term ‘glocalization’ – a mix of the global and the local - has

gained prominence in recent years.

We might therefore argue that Schumacher’s call for a new style to bring to an end the ‘series of relatively

short-lived architectural episodes that included Postmodernism, Deconstructivism and Minimalism’ is

itself at risk of being co-opted by that which it seeks to resist [12]. In other words, just as Deconstructivism

and Minimalism – far from resisting Postmodernism - can be seen to be the products of Postmodernism,

so too Parametricism could be seen to be complicit within the logic of Postmodernism. Is the new style of

‘Parametricism’ not the latest incarnation of the logic of Postmodernism?

Such a radical conclusion may not be so far fetched as it might seem. If loosely we are to define

Postmodernism as an obsession with the scenographic and appearances, we might see in Schumacher’s

repertoire of highly seductive formal terms – ‘continuous variation’, ‘seemless fluidity’, ‘deep relationality’ – a

concern not to overcome Postmodernism but simply to supply it with a new aesthetic language. If, however,

we are to subscribe to the recent thinking of philosophers such as Manuel DeLanda, who has developed

a discourse of New Materialism out of the materialist philosophies of thinkers such as Gilles Deleuze,

we might see that there is a new paradigm on the horizon [13]. This is a paradigm that focuses less on

formal concerns and aesthetics, and more on material behavior and design intelligence. It is a paradigm in

which performance – including both structural and environmental performance - is becoming increasingly

important, and one in which structural engineers, such as Cecil Balmond and Hanif Kara, have become the

new ‘material philosophers’. In the context of these new developments, Schumacher’s emphasis on a new

visual language seems a little dated.

Surely what the world of computation promises is not merely a new style, but a radically new way of

approaching design, where we embed new computational techniques into evolutionary and emergent

systems, and where we breed systems and test them out in real time, so that the diagram becomes the

reality and reality is the diagram. Form should be seen as largely irrelevant within this new horizon. Instead

we should be focusing on more intelligent and logical design processes. Logic should be the new form [14].

Neil Leach


注释

[1] I am deeply indebted to Nick Pisca for his advice on this article. Certain sections were cowritten

with him, and Nick has provided some invaluable feedback on the ideas expressed here.

[2] The term ‘optimization’ should be used with a degree of caution. It is often impossible to

know what the optimum might be, and much depends on the parameters being used to judge

that optimum. As those parameters vary, so the definition of the optimum will also vary. Instead

of thinking in terms of optimized solutions we should perhaps refer to ‘improvements’. A more

appropriate term might therefore be ‘ameliorization’ (from the Latin, ‘melior’, meaning ‘better’),

rather than ‘optimization’ (from the Latin term, ‘optimum’, meaning ‘best’). Here, at any rate, the

term ‘optimization’ is used to refer not to the act of finding the optimum solution, but rather to the

process of searching for it.

[3] In the case of Postmodernism, a word used to describe the aesthetic reflex of Postmodernity,

an era generally categorized by cultural theorists as a moment in which everything is co-opted into

images and commodities, the term was promoted by writers such as Charles Jencks, and used

to describe a new style of architecture. In the case of Deconstruction - a mode of philosophical

enquiry that was premised on the notion of challenging the value-laden hierarchies within Western

metaphysics – the term was adopted by the publishing industry, and somehow became charged -

for a short time at any rate - with describing a new formal language in architecture.

[4] Patrik Schumacher, ‘Parametricism: A New Global Style for Architecture and Urban Design’ in

Neil Leach (ed.), Digital Cities, Architectural Design, Vol. 79, No. 4, July/August 2009, pp. 14-23.

[5] Ibid.

[6] Schumacher, p. 23.

[7] Schumacher, p. 15.

[8] Ibid.

[9] We might argue, for example, that the generic appearance of a bicycle is not a consequence

of some arbitrary aesthetic decision making process, but of the material configuration of the

bicycle itself, as a machine designed to offer an efficient form of leg-powered transportation.

In other words, although some form of stylization is inevitable in the design process, the form

has evolved into a more or less stable state primarily through a consideration of mechanical

efficiency.

[10] On this see Jean-Fran鏾is Lyotard, The Postmodern Condition: A Report on Knowledge,

Minneapolis: University of Minnesota Press, 1984.

[11] Fredric Jameson, ‘The Constraints of Postmodernism’ (extract) in Neil Leach ed., Rethinking

Architecture, London: Routledge, 1997.

[12 ] Schumacher, p. 15.

[13] For a discussion of New Materialism, see Neil Leach, ‘New Materialism’ in Neil

Leach, Xu Wei-Guo (eds.), (Im)material Processes: New Digital Techniques for Architecture,

Volume 2: Students, Beijing: China Architecture and Building Press, 2008.

[14] I am indebted once more to Nick Pisca for this slogan.