Exploring Parametric Design to propose an Urban Development Plan located in Sydney

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EXPLORING PARAMETRIC DESIGN TO PROPOSE AN

URBAN DEVELOPMENT PLAN

LOCATED IN SYDNEY

TESI DI LAUREA Cristina Braccini UNIVERSITÀ DI PISA Scuola di Ingegneria DESTEC CdLM in Ingegneria Edile-Architettura a.a. 2015/2016 RELATORI

Prof.Ing. Marco Giorgio Bevilacqua Arch. Massimiliano Martino Arch. Dirk Anderson

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0 _ INTRODUCTION

My interest in Parametric Design, and thus my will to go through its use and the consequences it causes in architecture and particularly in urban design, comes from an internship experience I lived in the Urban Future Organization office in Sydney, Australia, in 2015. The directors of the office, architects, lecturers, and researchers, introduced me in the world of Parametric Design through the use of the software Grasshopper (McNeel & Associates), which I had the chance to use in the everyday practice in the office, and which thrilled me at the point I decided to write my thesis on it.

Figure 1. Parametric screen in UFO’s Sydney

office, UFO.

Figure 3. Voronocity project, UFO.

Figure 2. Parametric self-sustaining light in

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“Computation is about exploration of indeterminate, vague, unclear, and often ill-defined processes; because of its exploratory nature, computation aims at emulating or extending the human intellect. It is about rationalization, reasoning, logic, algorithm, deduction, induction, extrapolation, exploration, and estimation. In its manifold implications, it involves problem solving, mental structures,

cognition, simulation, and rule-based intelligence, to name a few.” Kostas Terzidis, Algorithmic architecture, xi

Nowadays the use of algorithms is becoming increasingly common in the practice of architects, besides its already good diffusion in the engineering and industrial design. Architects’ and designers’ dependence on computers is a fact; the use of CAD (Computer-Aided Drafting) software is something students learn as one of the primarily instrument for design; personal computers are the dearest and best friends of designers, and the way human mind and artificial machine communicate is continuously evolving and improving, granting an increasingly deep connection between the human and the artificial brain.

The algorithmic logic and use, while not necessarily dependent on computers, represents a good communication tool for architects and their computers, allowing designers in articulating a strategy for solving problems, often through the machine, the use of which being justified by the problems’ complexity, and amount or type of work required.

Algorithms are not only a mean for articulating problems, but also a mean of exploration of problems through the designer’s logic, creativity, and identity in terms of previous experienced designs, offering hints, suggestions, or alternatives that the human designer may never achieve. In other words, algorithms in design can be used to solve, organize, and explore problems, also allowing an increased visual and organizational complexity of models.

Parametric Design is leading to a change in the architecture practice, being “a powerful methodology to achieve a new architectural morphology, namely a morphology of continuous differentiation”1_{, to the point that Architect Patrick} Schumacher has claimed Parametric Design is defining a new style in architecture,

Parametricism, the first great new style after Modernism. What is definitely true

1. P. Schumacher, Design Parameters to Parametric Design, London, The routledge Companion for Architecture Design and Practice, 2014, p.1

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about designing with algorithms and parameters is the new approach it leads architects to, requiring a different way of tackling problems and resulting in a multiplicity of solutions for one single problem, within which designers can choose. This approach is applicable at very different scales in design, from industrial design, to mechanization of production, going through all the architectural and engineering design fields until large scale urban development and planning. Parametric urban design is a relatively young practice, main topic of several research programs all over the world. Thus projects of urban design tackled with the parametric approach are still mostly developed in the research environment. Some of the most active research centers for parametric urban planning can be identified in the Architectural Association2_{of London, the Aalborg University}3_in Denmark, and the Architecture Faculty in Lisbon4_.

A special mention is thus deserved by the Zaha Hadid Architects office, one of the most famous practices using Parametric Design in architecture. Besides the important theoretical work carried forward mainly in the published work of Patrick Schumacher, ZHA has also been proposing several competition winning masterplan projects in the last few years, in that realizing concrete outputs by using the parametric methodology.

2. MArch Degree in Architecture and Urbanism, Design Research Lab (DRL) at Architectural Association. 3. Faculty of Engimeering and Science, Department of Architecture, Design and Media Technology.

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0.1 _ PROBLEM DEFINITION

The research problem addressed in this thesis can be summarized as exploring the Parametric Design practice in urban scale projects, seeking to understand which are the main advantages and disadvantages Parametric Approach leads to the Urban Planning practice. The need for a deep understanding of such approach is driven by the popularity of parametric methods and the potential benefits acknowledged by several theorists, besides the complexity and time required when using parametric methods.

In order to gain an appropriate critical reasoning, a propose for an urban development of a site located in Sydney is realized. The proposed design conforms to the city of Sydney’s objectives for the area while utilizing parametric tools to aid inform generation and functional design layout.

The definition of a case study allowed the experimentation of a method developed from a detailed study of the actual ‘state of the art’, also analysing four selected example projects showing different parametric approaches to different urban problems, helping in gaining a better understanding about how a parametric model can be structured to solve urban problems.

The thesis is particularly referred to the use of the software Grasshopper (McNeel & Associates) as parametric mean of design, because this is the software I’ve had the chance to learn and use during my internship experience in Sydney, where the idea of this thesis was first conceived.

Parametric Design, as shown in the investigations forwarded in this thesis, can significantly improve the field of urban design by providing new tools of design investigation and form generation, even though some disadvantages will be pointed out.

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0.2 _ STRUCTURE

The study of the actual ‘state of the art’ starts in Chapter 1 with the History of Parametric Design in architecture, and the historical development of parametric software, which more than fifty years ago started changing, or to better say revolutioning, the design practice.

Chapter two aims to give an understanding of the means and logics involved when applying the parametric approach, reviewing published material from concerning applied use of Parametric Design, aiming to describe the main processes that are necessary in developing and solving problems with such approach. This chapter gives a general overview of Parametric Design, not specifically focusing on a particular field of design (industrial, architectural, urban, etc...).

In the third chapter a general description of the software Grasshopper (McNeel & Associates) is forwarded, briefly explaining the various typologies of components it is made of, also because those components will be recalled in following chapters when projects examples’ algorithm will be explored.

In chapter four the focus is moved to the practice of designing urban projects with parametric approaches. To better understand which advantages Parametrics leads to the Urban Design, the main issues occurring when designing contemporary cities are pointed out, again with the use of literature and published materials, mainly coming from practice, i.e. derived by personal experiences of many authors. Again the state of the art analysis is a mean of understanding the different approaches and methods the Parametric Urbanism is made of, and some of the main practices and researchers’ work in this fields are quoted to deeper understand such approaches and methods.

Chapter five, Parametric in Practice, explores some selected example urban design projects, all realized with the software Grasshopper. Selection of projects was based on some defined necessities, that are of course the use of the mentioned software, the intention of analyze different scale projects with different complexities in the structure and outcomes, and the need of picking the example projects in the research field, where design is free from many of the practical constraints that the practice has to face, such as stackeholders’ issues, or construction constraints, etc...

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0.3 _ ANALYSIS METHODOLOGY

The reference projects are analyzed with the following methodo:

- Introduction to the project, the author, and the research environment where the project has been developed in;

- Description of the intention or goals of the project, named Function description;

- Description of the parts or components the definition comprises of, named Structure description;

- Description of the way in which the components achieve the goals and intentions, that is the actual process of development of the project, named Behaviour description;

- Schematical representation of the algorithm structure, pointing out the software tools and components used and the relationships built between those, named Parametric Structure’s Analysis;

- Personal critical understanding of each project, explaining the main achievements of it, either in terms of outcome and technique. The thesis proceeds in chapter six with the definition of the case study project located in Sydney, first reporting all the informations gathered about the site and the authority’s (city of Sydney) objectives for the area, and from there developing a proposal solution of the problem.

The thesis’ conclusion are finally pointed out in chapter eight, where advantagies and disadvantagies are also described and a critique of the developed case study is made, also trying to give some directions concerning future work.

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1 _ What is Parametric Design?

1_ WHAT IS PARAMETRIC DESIGN?

“It is only comparatively recently that architecture has rediscovered the value of constraint systems as a way of representing geometric relations as a form of ‘design intent’, independent of particular geometric instantiations. There are other precedents for rather tenuous and discontinuous relationship between technology and architecture. We might also ask how many centuries after the building of

Pantheon did it take before concrete was ‘accidentally’ rediscovered?” Robert Aish, 2011.Designing at t + n, Architectural Design, November/December

2011, p.25

Robert Woodbury starts the second chapter of his book Elements of Parametric

Design with the question “what is parametric modeling?”5_{. He spends 12 pages on} the question, but instead of directly answer, he explains the workings of forward-propagating parametric models. Even though Elements of Parametric Design is one of the seminal books on parametric modeling, an expert as Robert Woodbury finds difficult to articulately answering basic questions like “what is Parametric Design”? The term parametric originates in mathematics, derivative from the term

parameter, ‘a quantity constant in the case considered but varying in different

cases’. Roland Hudson, in his thesis Strategies for Parametric Design in architecture defines a parameter as “any measurable factor that defines a system or determines its limits”6_{. Hudson then focuses on the meaning of design: in architecture, design} involves a response to a problem that is often not clear. Architectural design is “a matter of finding and solving problems”7_{, developing an understanding of the} problem and then generating many alternative solutions amongst which a solution can be selected.

Hudson thus ends up defining Parametric Design as a process where variables are used in describing and solving a design problem and by changing these variables 5. R. Woodbury, ‘Elements of Parametric Design’, Routledge, 2010, in D. Davis, ‘A History of Parametric’, [web blog], http://www.danieldavis.com/a-history-of-parametric/, 2016 (Accessed February 2016).

6. R. Hudson, ‘Strategies for Parametric Design in architecture. An application for practice led source’, PhD Thesis, University of Bath, 2010, p.19.

7. B. Lawson, ‘How designers think: The design process demystified’. Burlington, MA: Architectural Press, 2006, in R. Hudson, ‘Strategies for Parametric Design in architecture. An application for practice led source’,

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a range of alternative solutions can be created, which is the meaning we intend to use in this thesis as well.

A parametric model, as an abstraction of reality, is a representation of a problem which defines the relationships and parameters in the design problem. Making changes to the variables results in alternative models, where a solution is selected based on some criteria which may be related, in the practice, to performance, ease of construction, budget requirements, user needs, aesthetics or a combination of these.

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1.1 _ A HISTORY OF PARAMETRIC DESIGN

Nowadays there is debate as to when designers initially began using the term

parametric. In 1988 Pro/ENGINEER, the first commercially successful parametric

software, was released by Parametric Technology Corporation, founded by mathematician Samuel Geisberg in 1985, but the real provenance of parametric, Robert Stiles (2006) argues, was in the 1940s’ writings of an Italian architect, Luigi Moretti.

Moretti founded the Istituto per la Ricerca Matematica e Operativa applicata

all’Urbanistica (IRMOU) in 1957 aiming to study Parametric Design (architettura parametrica), a new practice in architecture based on mathematic theories:

Moretti wanted to define relationships between the dimensions of a geometry dependent upon various parameters.

Daniel Davis, in the paper A history of parametric (2013) argues that the earliest example of Parametric being used to describe three-dimensional models can be found in mathematics. In James Dana’s 1837 paper On the Drawing of Figures of

Crystals the author explains the general steps for drawing a range of crystals and

Figure 6. A model for stadium N exhibited at the

1960 Parametric Architecture exhibition at the Twelfth Milan Triennal, Luigi Moretti.

Figure 5. Plans for stadium version M and N

showing the “equidesirelability” curves, Luigi Moretti.

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provisions for variations using language laced with parameters, variables, and ratios (Davis, 2013). In his paper Dana is describing parametric relationships in statements that explain how various parameters filter through long equations to affect the drawing of assorted crystals, resembling methods used 175 years later to develop parametric models of architecture.

In the early ninetieth century, according to Davis (2013), many other cases of parametric representation can be found, such as in the book on geometric analysis by Sir John Leslie (1821, 390), where the author proves the self-similarity of catenary curves using “parametric circles”. Leslie’s case is just one of the multiple examples of expressing geometry with parametric equations, well before Antoni Gaudí first began designing architecture with parametric catenary curves and parametric hyperbolic paraboloids at the end of ninetieth century.

Mark Burry, the current executive architect of Sagrada Família, underlies Gaudí’s deep understanding of mathematics, especially used in his later architecture, which almost exclusively consists of mathematical ruled surfaces such as helicoids, paraboloids, and hyperboloids, parametrically associated together with ruled lines, booleans, ratios, and catenary (J. Burry and M. Burry 2010).

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The best illustration of Gaudí’s use of parametric equations in architecture is his hanging chain model, containing all the components of a parametric equation, i.e. a set of independent parameters (string length, anchor point location, birdshot weight), a set of outcomes (the various vertex locations of points on the strings) which derive from the parameters using explicit functions.

With this model Gaudí could automatically compute the parametric outcomes rather than manually calculating the outputs from a formula, which is the biggest innovation in the use of parametric equations since then. Later this method of analogue computing was enlarged by Frei Otto.

Otto and Rash (1996) theorization on the structuring of space and unplanned settlements8_{, and their form-finding experiments in self-generated structures,} have inspired several investigations in architecture and urban design (J.V. Lopes, A.C. Paio, J.P. Sousa, 2014). Otto presents in Occupying and Connecting (2011) a theory about phenomena of urban networks as self-organized systems, surfaces and paths occupations, and territories expansion. All these spontaneous structures grow through two basic processes that organize all natural and humanized spaces: occupation and connection.

8. Otto and Schaur worked on the research program SFB 230 “Natural Structures”, sub-project C2 “Natural Processes – House and Town” at the Institute for Lightweight Structures (IL) at University of Stuttgart. The IL

Figure 9. Soap film model of form-finding, Frei

Otto.

Figure 8. Polystirene chips modeling showing

distancing and attractive occupations, ILEK Stuttgart, Frei Otto.

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These models of form-finding foregrounds the exploratory nature of parametric modeling, to the point that Schumacher, in Parametricism as a style – Parametricist

Manifesto (2008) claims that “the only precursor of Parametricism is Frei Otto”.

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Davis (2013) attributes to Gaudí’s and Otto’s work the development of models that form an important component of the parametric modeling dogma for architects, namely the utility of parametric models lies in the exploration of outcomes. These analogue parametric models all have a set of quantities expressed as an explicit function of a number of independent parameters, however this is complemented by a utilitarian emphasis on exploring the possibilities offered by the model.

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1.2 _ A HISTORY OF PARAMETRIC SOFTWARE

The following step of the parametric revolution was the digitisation of computation, which represented a mean to facilitate calculations not possible with analogue parametric models.

The fatherhood of this innovation is assigned to Ivan Edward Sutherland, researcher in computer science and internet pioneer, who invented the program Sketchpad in the course of his PhD thesis in 1962 at the Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts. The Sketchpad system made it possible for a man and a computer to “converse rapidly through the medium of line drawings”9_. With Sketchpad designers could explore variations by modifying parameters and the program would automatically recalculate and redraw the geometry. Moreover, relationships inside the model were able to be modified thanks to Sketchpad, and this in turn would cause the recalculation and redrawing of the model.

9. I.E. Sutherland, ‘Sketchpad: A man-machine graphical communication system’, University of Cambridge

Computer Laboratory Technical Report, n. 574, 2003, p.17.

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2 _ Design with Parameters

Sketchpad used the so called atomic constraints by Sutherland (1963), which have the essential properties of a parametric equation, i.e. a set of outcomes as an explicit function of a number of independent parameters. Sutherland never referred to the word parametric, but he developed the first parametric software in terms of the approach Sketchpad is based on.

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During 1960’ and 1970’, according to Daniel Davis, the impact Parametric Design would have had on architectural practice in the following 50 years was still far to be imagined. Early commercial systems for computers replicating drafting tables were ways too expensive to be achievable by architectural practices. Only in 1982, “a time when computers were becoming affordable enough for some people to own a personal computer”10_{, AutoCad was released in its first version by Autodesk, with} commands enabling the designer to explicitly draft two-dimensional lines using a keyboard rather than a pen, as it was used by Sketchpad. In 2009 the eighteenth version of AutoCAD, AutoCAD2010, introduced a parametric functionality claimed as a groundbreaking new capability, more than forty years after Sketchpad.

Almost thirty years before AutoCAD2010’s new parametric modeling was presented, in 1988, Pro/ENGINEER was released by the Parametric Technology Corporation (PTC). Professor Samuel Geisberg, founder of PTC, during an interview with Industry Week captured the motivations of parametric modeling, expressing the goal of Pro/ENGINEER as to create a system flexible enough to encourage the engineer to easily consider a variety of designs.

In 1993 Dassault Systèmes released CATIA (Computer graphics Aided Three-dimentional Interactive Application, first released in 1981) version 4, which had quite big diffusion for that time (8000 customers11_{) incorporating many of the Pro/} ENGINEER’s parametric features. At that time Rick Smith, a CATIA expert originally from the aerospace industry, was helping Gehry Partners realising geometrically challenging architecture such as the Barcelona Fish (1991) and the Guggenheim Museum in Bilbao (1993-97).

10. D. Davis, ‘A History of Parametric’, [web blog], http://www.danieldavis.com/a-history-of-parametric/, 2016 (Accessed February 2016).

11. F. Bernard, ‘A short history of CATIA & Dassalut Systèmes’, [website], http://ridwan.staff.gunadarma.ac.id/ Downloads/files/8426/history-catia.pdf, 2003. (Accessed April 2016).

Figure 13. Structure analysis with Pro/Engineer. Figure 14. Beijing National Stadium 3D model

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Using these works as bases, the Gehry Partners team created Gehry Technologies in 2002, forwarding a new, technology driven approach to delivering complex building projects. “By adopting methods and technologies from automotive and aerospace, working directly in a shared 3D digital environment, and collaborating across discipline lines to bring fabrication expertise forward into design, the architectural firm realized unprecedented projects with tight control of budgets, schedules and quality”12_{. The Gehry Tecnologies released in 2004 the parametric} modeling software Digital Project, with the aim of create a mean for architects for rationalise geometry as characteristically complicated as Gehry’s. Davis (2013) argues much of Digital Project relies on CATIA version 5’s parametric engine, which enables the revision of parameters and equations, so that designer’s geometry

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can be better controlled, in much the same way Pro/ENGINEER has already helped engineers.

Besides the availability of several parametric software, the vast majority of architecture firms was using computers just for drafting and coordinate drawing sets (Davis, 2013). Still some specialist building modeling software such Revit and ArchiCAD were chosen by some architects.

Some former developers of Parametric Technology Corporation decided to create the “first parametric building modeller for architects and building design professionals” (Revit Technology Corporation 2000a) and founded the Revit Technology Corporation in 2000. The name ‘Revit’, intended as the action of revise instantly, represents the essence of what the authors intended to achieve in developing this software, defining parametric as an object based on parametric equations that the designer can adjust to particular changing circumstances. Revit distance from other software like CATIA or Pro/ENGINEER in the fact that parametric relationships, although existing, are hidden behind the interface, because the focus of the software is not on creating parametric models, but just on their use in the design process.

In 2002 Revit was acquired by AutoDesk, which first invented the name Building Information Modeling (BIM) in declaring their brand of design, which is distinguished from parametric modeling in the emphasis on the management of information rather than managing the parametric model itself.

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During the last few years other software packages have made their way in the daily practice of architecture, specially through the scripting interfaces, which allow designers to write codes to automate parts of the software. The script, with input parameters, explicit functions, and outputs, is indeed an archetypal embodiment of the mathematical definition of parametric. Ipek Dino (2012) has argued scripts are inherently parametric, noting that “parametric systems are principally based on algorithmic principles” since “an algorithm takes one value or a set of values as input, executes a series of computational steps that transform the input, and finally produces one value or a set of values as output”13_.

Visual programming is a particular type of scripting interface that allows designers to specify a sequence of relationships and operations to automate the construction of the geometry. The name “visual” comes indeed by the possibility of represent script models not as text but rather as diagrams, making its management much easier. The exploration of design options is facilitated by visual scripting, in that the designer is able to change the inputs to the script and to produce the desired shape for the geometry, having the change to effectively visualize the changes. The first notable visual scripting software developed for the architecture practice can be identified with Generative Components, developed by Bentley Systems and first released in 2003. This software was developed with the intention to provide an environment of parametric modeling where variables, constraints and relationships between elements are clearly defined. With the words of Yalinay Cinici

et al. Generative Components ”provides an intermediate level of computational

13. İ. Gürsel Dino, ‘Creative design exploration by parametric generative systems in architecture’, 12 January

Figure 17. Windows XP

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use. So there arises an answer to the question ‘designer or coder?’ in terms of which designer can also code algorithms in a visual and symbolic way without losing control over the design object”14_.

Grasshopper, the visual scripting interface developed by David Rutten for Robert McNeel & Associates in 2007, first released as Explicit History, is another very used visual scripting software. Grasshopper, as Generative Components, is based around graphs that map the flow of relations between parameters, through user-defined functions, normally generating a geometry as output; when changes to parameters or model’s relationships are made, the software automatically redraw the geometry.

Further in this thesis it is considered the use of the software Grasshopper in urban design.

14. S. Yalinay Cinici, F. Ozsel Akipek and T. Yazar, ‘Computational design, parametric modeling and architectural education’, Arkitekt Temmuz, August 2008, p.5.

Figure 18. Bentley Systems Generative Components’s visual programming environment.

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3 _ Parametric Urbanism

2 _ DESIGN WITH PARAMETERS

“Initially, a parametric definition was simply a mathematical formula that required values to be substituted for a few parameters in order to generate variations from within a family of entities. Today it is used to imply that the entity once generated

can easily be changed.” Yessios 2003, 263

Patrick Schumacher in his paper Design parameters to Parametric Design (2014), states that Parametric Design is an approach to architecture problems that treats the geometric properties of the design as variables that can always change as the design progresses, the parameters.

Parametric Design thus moves the focus of architects’ practice on the network of relations and dependencies existing in a parametric model, rather than the formal result of the process of design. As Daniel Davis underlines in his thesis (2013) “the pivotal part of a parametric equation is not the presence of parameters but rather that these parameters relate to outcomes through explicit functions”. For Davis the first observable characteristic of designing with parameters is indeed the fundamental importance of explicit relationships.

Another characteristic of a parametric model can be expressed with the words of Robert Woodbury: “Design is change. Parametric modeling represents change”. In the parametric modeling environment geometry changes when the parameters change, and this leads some to claim that change itself is parametric. However the real innovative statement introduced by parameters in design practice is that the multiple parts of the design, called marks, “relate and change together in a coordinate way” (Woodbury 2010). Robert Aish (2011) has similarly emphasized the importance of variation by saying a parametric model “directly exposes the abstract idea of geometric ‘transformation’.”

Besides the evidences of Parametric Design, the question this chapter aim to answer is what does really mean designing with parameters?

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(2010), delineates the tasks related to the definition of a parametric model as a representation of a design problem in terms of functions, requirements and constraints, which need to be identified and expressed through parameters. Hudson’s work can be seen as an answer to our question in the way he analyses the process of design with parameters.

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2.1 _ PROBLEM DESCRIPTION

The starting point when designing with parameters is to create the model developing a description of the design problem, starting from some initial ideas that instigate the process and suggest some form of abstraction where function, structure, and behaviour of the project are assigned, parameters are identified, and a parametric model can be constructed and studied.

Lawson (2006) claims that, when it comes to architectural design, it is difficult to state the problem at the outset, so that this can potentially bring to an infinite set of possible solutions. Architectural design solutions are indeed a result of negotiation between problem description and solution. In his study of designers in practice, Lawson (1994) observes that the ability to select the right problem in architecture is strictly necessary for success. Thus, this phase acquires primary importance as “professional practice has as much to do with finding the problem as with solving the problem found”15_.

With the model it is possible to explore the problem space: all design problems are solved by searching a large space of possibilities; these spaces exist within the task environment or context and are called solutions or problem spaces. As the task environment for architectural problems is generally complex, the size of the solution space can be immense, generating ill-structured problems, for which is required to clarify, define and redefine the problem until its goals and means are clear at the outset. The problem space is further analysed later in this thesis. As said before listing all the requirements at the outset can be difficult or even impossible in the practice as what is actually known at that stage might be little. Many authors have investigated this process proposing different approaches. Jones (1992)16_{proposes a model in three parts that deals directly with the} production of ideas: divergence, transformation and convergence. First step is to diverge from what exists in terms of a problem description so that objectives and problem boundaries are discovered. From this new understanding of the problem and by splitting the problem in sub-tasks and identifications of constraints related 15. Schon, D., ‘Reflection in action’, cited in Davis, D., ‘Modelled on Software Engineering: Flexible Parametric Models in the Practice of Architecture’, Thesis, RMIT University, 2013.

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to each task, the design brief can be refined. Each set of sub-tasks represents an alternative structure to impose to the problem. The last step, convergence, aims to reduce the range of options previously generated into a set of rational options and selecting one from these.

Hillier et al. (1978) proposed a model for pre-structuring a design problem, which involves defining a speculative theory as a starting point, and then analyse the resulting model to check whether it can be used to develop designs that conform to the specific requirements.

Another means for idea generation is proposed by Darke (1978)17_{, originating from} her studies of the design processes for a series of residential buildings, in a way to start the problem based on an original understanding or visceral notion of the problem, and then examining it to see what it suggests about the problem: this method is called “primary generator”.

Heuristics methods can describe another approach to the problem description where a particular idea is considered valid until proven false, relying on experience and rules of thumb rather than theory.

Gero (1990)18_{uses three formal categories to tackle the problem description, in} that identifying functions, constraints and requirements: he calls those categories function, structure and behaviour, which together form a “design prototype”. Function relates to the intention or goals of the artefact; structure concerns the parts or components that the artefact will comprise of; behaviour concerns that way in which the structure achieves the function. Gero’s categories are used forward in the thesis to analyse the case studies.

The design prototypes proposed by Gero are in fact formal descriptions of problems as a means of establishing a design process. Thus a prototype is not to be intended as a design itself but just as an accurate and sophisticated problem description. Usually more than a prototype is produced for one problem, starting from an initial set of function, structure, behaviour built on the client’s functional specifications 17. Darke, J., The primary generator and the design process. Pages 325–337 of: New directions in environmental design research: Proceedings of edra 9, 1978, cited in Hudson, R., ‘Strategies for Parametric Design in architecture. An application for practice led source’, PhD Thesis, University of Bath, 2010.

18. Gero, J., ‘Design prototypes: A knowledge representation schema for design’, Ai magazine, vol. 11, no.4, pp. 26–36, 1990, cited in Hudson, R., ‘Strategies for Parametric Design in architecture. An application for practice led source’, PhD Thesis, University of Bath, 2010.

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or an existing solution from a similar problem. The retrieved prototype is thus adapted to the new problem, i.e. on the analysis and knowledge of the condition of the current problem.

An important step in the problem description process proposed by Gero is the partition of the problem in multiple sets of sub-tasks, with a typical bottom-up approach, where components or sub-assemblies are interlinked to form a global geometry. For Gero defining partitions is largely dependent on the designer’s experience of the particular design problem and it allows the problem space to be reduced because only information relating to each partition is used to solve the part.

For a more thorough understanding of the design problem it is undoubtedly better to underlie the principles of the design in greater details, resulting in a formal representation of design ideas. There are contrary opinions thoughts about the position the problem description process needs to assume in the global design process. Some believe complete problem descriptions are required before parametric modeling can begin, while others see the understanding of the problem as a gradual process in which parametric modeling assists the designer. Hudson (2010) claims that the latter opinion is particularly evident when the design process requires an iterative model, where “subsequent designs are generated, evaluated and modified”19_.

Whatever approach is chosen by the designer for the problem description, the following step will be to find alternatives exploring the problem space and make a rational choice between them.

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2.2 _ PROBLEM SPACE

Given an understanding of the problem and an initial starting point for the process, it is possible to create a representation or parametric model. Lawson (2006)20_{claims a problem space is the model of a design, and it is defined by the} problem’s constraints representing the boundaries of the space. For Lawson there are different kinds of constraints for the design space, and they come primarily from the designers, the client and user, and from legislators. Designer’s task is to integrate and coordinate all the constraints. For Lawson one of the chief challenge in the practice of design is the development of a continuing developing design philosophy, able to absorb the special constraints peculiar to a particular problem.

Design constraints aim to ensure that the demanded functions are performed by the design system as adequately as possible. Following are the different typologies of constraints that Lawson points out in his thesis, which are largely resulting from required or desired relationships between various elements. First constraints are the internal ones, which traditionally form the basis of the problem as most clients tend to initially express it, thus represents the majority of the brief for designers. 20. Lawson, B., ‘How designers think: The design process demystified’, Burlington, MA:Architectural Press, 2006, cited in Hudson, R., ‘Strategies for Parametric Design in architecture. An application for practice led source’, PhD Thesis, University of Bath, 2010.

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Clients, which are usually the first generators of problems given some certain needs they are not able to find a solution for, request for various kinds and qualities of spaces, which designers have to define relationships between to structure the problem. External constraints are represented by influential and inspirational ones, not under the designer’s control, and are the very essence of the special unique circumstances that make a design different. Internal and external constraints define the freedom available to the designer in solving a problem. Both these constraints can be generated by designers, clients, users and legislators. There are other types of constraints such as radical and practical ones. The former deal with the primary purpose of the object or system being designed. Lawson calls those “radical” in the original sense of “at the root of” or fundamental. Such constraints can range over a tremendously wide set of issues and are very influential from the very beginning of the design process. Practical constraints instead are related with the reality of producing, making or building the design, i.e. technological problems, also embracing the technical performance of the designed object during its working life. Finally there are some constraints more related to the aesthetical result of the design: formal constraints and symbolic constraints. The former deal with the visual organization of the object, in terms, for example, of proportion, form, colour and texture. They can be said to deal with art and design in visual terms. At another end there are symbolic constraints, coming from the Post-modern tradition, which made use of historical styles as an attempt of reconnection with the past to overcome the contradictions of a more uncertain age.

The problem space is thus the internal representation of the task environment developed by the problem solver. Heath (1984)21_{suggests that design methods} in architecture should be concerned with the construction of the problem space, which needs to be manipulated in his definition by the designer, reducing in so doing the size of it and allowing a solution to be identified. Heath claims architectural problem spaces are ill-defined because they involve uncertainty both in terms of how the problem is tackled and which means or components are used to solve it. The exploration of the design space becomes the mean to find a solution for the correspondent design problem. Thus exploration is claimed to be the primary task for the designer (Kilian 2006a)22_{. It is forwarded using a design explorer, i.e. a} 21. Heath, T., ‘Method in architecture’, Chichester: Wiley, 1984, cited in Hudson, R., ‘Strategies for Parametric Design in architecture. An application for practice led source’, PhD Thesis, University of Bath, 2010.

22. Kilian, A., ‘Design exploration through bidirectional modeling of constraints’ PhD thesis,Massachusetts Institute of Technology, 2006a, cited in Hudson, R., ‘Strategies for Parametric Design in architecture. An

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parametric software, described by Kilian as a “physical or computational construct that combines design representations and constraints in order to support design exploration within the defined conditions”. Indeed Aish and Woodbury (2005) describe this step of the design as explicitly developing relationships between objects, constructing a control rig rather than the geometry of the object itself. Literature reports many different approaches to the task of exploration. For Gero (1990) exploration is about seeking which variables might be appropriate, as the process begins with assignment of values to parameters in accordance with given requirements and constraints.

Burry (2003) claims that all design tasks are concerned with evaluating a range of parameters. This task can thus be inhibited by the enormous size of the design solution or design space (Chandrasekaran, 1990).

Newell et al. (1957)23_{claim the process of problem solving is in fact the movement} from the context within which the problem exists, or “task environment”, to a problem space, where problem solving takes place as search. The search can follow many different methods, which are organised and controlled by the designer. Newell

et al. propose three general search methods inside the problem space: recognition

of solutions, generate-test and heuristic search. Former consists in the knowing of the answer, and happens in later stages of design, when the size of problem space has been reduced. The generate-test is an iterative method of production of solution, which are then tested based on the problem’s requirements. In that the requirements need to be known. The latter method, heuristic search, is useful in large problem spaces. It makes use of information from personal experience to guide the search in steps that reduce the number of alternatives. Once an acceptable range of possibilities is found, the generate-test or recognition methods are then applied to find the solution.

23. Newell, A, Shaw, J.C.,and Simon, H.A., ‘Elements of a theory of human problem solving’,Rand Corporation, 1957, cited in Hudson, R., ‘Strategies for Parametric Design in architecture. An application for practice led source’, PhD Thesis, University of Bath, 2010.

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2.3 _ ALTERNATIVES: GENERATION AND ASSESSMENT

As said before, the exploration of the design space generates multiple options or alternatives, which are then assessed to establish their appropriateness. Assessment involves subjective interpretation that either results in further understanding of the design problem or suggests a new direction (Lawson, 1994). Schon (1991) believes that professionals can develop an understanding of a design problem using a series of small scale mental experiments which allow the rapid generation and testing of alternative design ideas. According to Jones (1992) later stages of the design process are coupled with an internal feedback mechanism, based on the outcome of each previous cycle.

Simon in Style in design (1975) defines a method where a set of constraints are identified, enabling satisfactory solutions to be determined, and once elements are generated they are first tested to see if they satisfy some of the constraints. If they does, they can be added to the design. A second test is then submitted to check if design progress is being made and which of the constraints remain unsatisfied. This then inform the next iteration where more constraints are added or removed. Such a program can be a computer program or may exist in the head of the designer.

Chandrasekaran (1990) developed a method in three phases, Propose-Critique-Modify, concerned with assessment and then change, based on the results of assessment. Critique is a verification of the satisfaction of functions and other specifications; if functions are not satisfied the proposal is modified accordingly, in a diagnostic process where areas of failure are identified: the way in which a design fails directs the modifications that are subsequently made.

However the process of assessment requires the designer to consider both the way in which the evaluation is undertaken and the way in which they respond and make subsequent changes to the model. Evaluation will indeed indicate how to modify the design.

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3 _ PARAMETRIC URBANISM

“We propose a discipline of urban design which is different, entirely, from the one known today. We believe that the task of creating wholeness in the city can only be dealt with as a process. It cannot be solved by design alone, but only when the

process by which the city gets its form is fundamentally changed”. Alexander et al. The nature of order, 2003-04, p.3

Parametric Design is being increasingly applied in architectural and commercial design, and is already well established in engineering, while in urban design it’s still in his relative infancy (Steinø, 2010), even though the first dedicated commercial software are now emerging, such as CityEngine27_{, CityCAD}28_{, etc… In this chapter} an idea of the implications of using Parametric Design in urban projects is given, starting from the main features of urban design projects.

3.1 _ URBAN DESIGN

Urban design, with the words of Jonathan Barnett, emeritus Professor of Practice in City and Regional Planning, is “designing cities without designing buildings”. Urban designs are often conceptual designs defining overall principles for urban development, rather than producing high detailed objects as architectural or product design do. Moreover urban design is concerned with how places function, not just how they look, resulting in three dimensional forms and space and enhancing the life of the city and its inhabitants.

Cities can be described as accumulations of events, changing processes, overlapping juxtapositions, and so forth29_{; dynamic systems continuously changing, adapting to} different social and economic conditions. Thus cities can’t be planned according to static rules, or by using fixed prescribed masterplans, as many utopians author in 27. CityEngine is a three dimensional modeling software application developed by Esri R&D Center Zurich, formerly Procedural Inc., first released in the version of Pascal Mueller in 2008.

28. CityCAD is a urban design software tool for conceptual 3D masterplanning developed by Holistic City Limited companyin 2010.

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history have claimed (Shnabel and Karakiewicz, 2007). Descriptions of organic or adaptable systems would be much closer to reality for informing the generation of desirable outcomes, in terms of intelligent solutions to the urban problem. (Batty and Longley, 1994).

Besides the adaptability, complex settings of most urban design require the process to be argumentative, collaborative and inclusive in order to achieve a viable design. The designed system needs to remain open as long as possible for alterations as a result of negotiations with stakeholders, because of the economic and time effort that a complex design requires to be altered (Steinø & Veirum, 2006).

Another main issue of urban design practice is related to the participatory aspect. Contemporary urban space is becoming increasingly complex in its creation and use, as involving many different services, and consequently different professional, as made up of construction, management, transportation and communication services. Moreover, besides professionals, urban design involves many layperson such as stakeholders, developers, residents, and any other figures with an interest in urban development (Steinø, Yildirim and Özkar, 2013). Urban design is thus becoming increasingly collaborative and participatory.

Collaborative planning has been theorized by many authors as an instrument to relate contemporary urban design and planning practices in the complex contest of contemporary cities (Rasmussen, 2012). Urban governance practices and institutional design can be embed in more democratic planning processes30_, through which “ways of thinking, ways of valuing and ways of acting are actively constructed by participants”31_.

As a consequence of the collaborative behaviour that urban design is assuming nowadays, when facing urban design problems involving all those participants, the process of validation of the design becomes a main issue, being the design often negotiated among several stakeholders. Validating an urban design may become a hard job, as not all urban design criteria are necessarily quantifiable, and as the 30. Healey, P., ‘Collaborative Planning - Shaping Places in FragmentedSocieties’, Macmillan press, 1997, in Steinø, N., and Obeling, E., ‘Parametrics in Urban Design - A bridge to Cross the Gap Between Urban Designer and Urban Dweller?’, AESOP Conference, no.5, Vienna, 2005. Available from ResearchGate, (accessed May 2016).

31. P. Healey, ‘Collaborative planning - Shaping Places in Fragmented Societies (second ed.), Macmillan press., Hampshire, U.K. , 2006, cited in C. Rasmussen, ‘Participative design and urban planning in contemporary

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goals of urban design cannot necessarily be agreed upon among stakeholders. Winy Maas, co-founder of one of the most famous urban planning firm of our days, MVRDV32_{, in the book KM3 explores new ways of thinking and solving urban} problems, introducing a new urbanism aiming to realize a city that is continuously under construction, with space for limitless capacities, and populations. Maas points out two main challenges in contemporary urban design. On the one hand cities are growing and mutating entities and urban design needs to respond to these changes, and on the other hand, from a more theoretical point of view, a challenge is the definition of the notion of the public realm itself, after modernistic and idealistic urban visions from 1960’ failed. Maas observes the need for new urban theories, considering the possibility to include the latest technologies, such as modeling programs, to understand and evaluate interactions and relations in design and processes in urban planning. The dynamic interaction of components and actors is referred to as a way to address complexity of cities, thus Maas proposes the development of a virtual platform simulating interactive urban developments and allowing the exploration of the reactions in complex and global urban networks.

Indeed MVRDV develops its work in a conceptual way, the changing condition is visualised and discussed through designs, sometimes literally through the design and construction of a diagram. The office continues to pursue its fascination and methodical research on density using a method of shaping space through complex 32. MVRDV is an architecture firm based in Rotterdam, founded in 1993 by Winy Maas, Jacob van Rijs and Nathalie de Vries.

Figure 21. Porous city Lego Towers, Venice Biennale Architecture Exhibition 2012, Venice, Italy,

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amounts of data that accompany contemporary building and design processes. The firm uses computer software to generate endless possible architectural and urban configurations.

3.2 _ PARAMETRIC URBAN DESIGN

In the previous part of the thesis the main challenges designers find when facing urban problems have been explained. It is clear that a parametric approach to urban design can result very suitable. Firstly it allows scenarios to be easily tested and modified without much time effort; secondly it facilitates collaborative design and make the discussion between the many participants easier, the designers being able to change and evaluate their design quite fast, meanwhile producing clear and quite complex outcomes from the early stages of the design process. Nowadays the discussion about a parametric approach in urban design is lit up and many authors and researchers have written about the consequences and utilities such approach lead in the practice of urban design.

Burry (2005) suggests that Parametric Design allows designers to rapidly evaluate design scenarios based on a combination of datasets and rules, in an iterative design process of defining and adjust parameters and relations. The parametric approach substantially move the research focus from the concept of type to one of process, thus design is transformed into a sort of definition of intelligent rules (Fusero, Massimiano, Tedeschi, Lepidi, 2013). This method can be applied to design at all scales, including the urban one.

Beirão (2011) claims that the method of parametric urban design has been developed to involve the use of urban data to facilitate an interactive design system, where geometries are updated instantly according to changes in data or design criteria, whether it is GIS data or stakeholders feedback. The capacity of rapidly generate new geometries let the designs go through more iterations than when using traditional design methods, potentially improving the quality of the design (Burry, 2005).

For Speranza (2014) the parametric methodology can facilitate the traditional beginning studios for urban design. The new parametric tools indeed allow

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drawing upon existing data sets and gathering and analysing data both in situ and off site, for a better understanding of the phenomena of a place, defined as the real-time, everyday experience and behaviours (Norberg-Schulz 1976). Social and natural phenomena occurring in the urban environment can be codified with a simultaneous integration of analysis and synthesis methods with design solutions. This in turn leads to an understanding of urban phenomena over time such as transit, weather or people’s behaviour. Speranza proposes a parametric methodology that “not only inform analytical decision making but identifies urban characteristics that design proposals may support through design strategies including: the use of materials to affect the experience of people, acknowledge environmental forces, the visualization of data in public space, the use over time, and other design strategies”33_.

3.2.1 _ PARAMETRICISM

Particularly important both on the experimental and theoretical side, is the work of Zaha Hadid Architects practice, in the contest of which a theoretical and methodological procedure for parametric urbanism has been developed. In their work, directors Zaha Hadid and Patrick Schumacher have developed a series of urban projects that explore either the typological vocabulary of urban tradition and the Parametric Design system, aiming to develop new urban forms or new urban complex geometries (Silva, Amorim, p.3).

33. P. Speranza, ‘Using parametric methods to understand place in urban design courses’,Journal of urban

design, 9 December 2015, p.2. Available from Taylor & Francis online. (accessed March 2016).

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From a theoretical point of view Patrick Schumacher claims parametric approach is a paradigm penetrating into various disciplines, especially in urban planning, and renames it Parametricism, “the new style after Modernism” emerging from using Parametric Design systems finalized in articulate increasingly complex processes. With the words of the author, Parametricism is “a new style rather than merely a new set of techniques. The techniques in question – the employment of animation, simulation and form-finding tools, as well as parametric modeling and scripting – have inspired a new collective movement with radically new ambitions and values. (…) Over and above aesthetic recogniseability, 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”34_.

Parametricism is the embodiment of parametric thinking and parametric software, which can be utilized at all scales and applications of design, ranging from interior design to large scale urban planning: “the larger the project, the more pronounced is parametricism’s superior capacity to articulate programmatic complexity”.35 Schumacher believes that the computer explorations allow the combination of all contextual design factors of site, including social and cultural aspects, and the generation of various design proposal adjustable since the ideal outcome is found. In 2008 Schumacher presented the Parametricist Manifesto in the contest of the XI Architecture Biennale in Venice, Out there: Architecture beyond building.

34. P. Schumacher, ‘Parametricism: A New Global Style for Architecture and Urban Design’, Architectural

Design, 79/4, 2009, p.15.

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5 _ Parametrics in practice

In his Manifesto Schumacher proposes a new slogan for avant-garde architecture and urbanism, which claims the key issues of these practices are organising and articulating the increased complexity of post-fordist society, with the objectives of create complex polycentric urban and architectural fields densely layered and continuously differentiated.

The conceptual definition of Parametricism as a style is explained by Schumacher (2016) by saying that all architectural elements and compositions are parametrically malleable, in that shifting from the classical and modern reliance on ideal geometrical figures to new primitives that are animate (dynamic, adaptive, interactive) geometrical entities. Consequently dynamical compositions of fundamental geometrical building blocks reacts to “attractors” and can be made to resonate with each other via scripts. In principle every property of every element is subject to parametric variation through the use of new software and techniques, even though Schumacher specify Parametricism “cannot be reduced to the mere introduction of new tools and techniques”36_{. In fact new ambitions} and values, in term of both form and function, characterize the new style. Software and instruments such as scripting techniques are means to lawfully differentiate and correlate elements and subsystems of a design, aiming to intensify the internal interdependencies within a design and the external affiliations and continuities in complex urban contexts.

From the operational point of view, Schumacher’s programme/style consists of methodological rules, as “each style has its hard core of principles and a characteristic way of tackling design problems/tasks”37_{. Parametricism is basically} based on negative rules, which represents paths of research to avoid, and positive rules, which are to pursue. These rules, called heuristics, are subdivided in formal ones and functional ones. Former establish rules and principles defined to guide the elaboration and evaluation of the development and resolution of the design process, while latter give rules and principles for the elaboration and evaluation of the design’s social functionality.

Both formal and functional heuristics are basically definable with some taboos to be avoided and dogmas to be followed, which finally deliver complex order to 36. P. Schumacher, ‘Design Parameters to Parametric Design’, The Routledge Companion for Architecture

Design and Practice: Established and Emerging Trends, 2016, p.8.

37. P. Schumacher, Parametricism as a style – Parametricist Manifesto, [website], 2008, http://www. patrikschumacher.com/index.htm. (accessed March 2016).

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the design, always subject to critique and improvement. Some examples of formal negative principles are to avoid rigid forms, repetition, or unrelated elements, while positive principles could be the informed deformation of forms, the differentiation of system, the necessary definition of interdependences between systems. Regarding functional heuristics, taboos are rigid functional stereotypes as well as definition of zoning segregating functions, while dogmas are to design functions that are parametric activities or event scenarios, and to make them communicate with each other (Schumacher, 2016).

Schumacher’s Parametricist Manifesto proposes five agendas as guiding paradigms aiming to help the further development of this new style in architecture. Following the agendas are briefly described:

1. Inter-articulation of sub-systems:

It is intended as the association of multiple subsystems such as envelope, structure, internal subdivision, in a way that “the differentiation in any one systems is correlated with differentiations in the other systems”38_{, moving from the single system differentiation.} 2. Parametric Accentuation:

By creating intricate correlations, the overall sense of organic integration is increased, reaching a better articulation of space and more orienting visual information. “For instance, when generative components populate a surface with a subtle curvature modulation the lawful component correlation should accentuate and amplify the initial differentiation. This may include the deliberate setting of accentuating thresholds or singularities”39_{. Indeed a key aesthetic} ideal of Parametricism is to create different elements and highlight their differentiation.

3. Parametric Figuration:

Complex configurations can be constructed as parametric models, where quantitative modification of parameters trigger qualitative shifts in the perceived order of the configuration (Gestalt-sensitive variables). Beyond the usual geometric objects parameters, Parametricism has to consider ambient and observer parameters. 4. Parametric responsiveness:

The design of the urban and architectural environments allows them to reconfigure and adapt themselves, responding to the 38. Ibid.

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prevalent pattern of use and occupation, i.e. to changes in the built environment. By registering use patterns, the built environment acquires responsive agency at different time scales.

5. Parametric Urbanism:

Using the previous guidelines to achieve deep relationality in the urban context, Parametric Urbanism is achieved as a complex articulation of relations within the entire urban fabric. “The assumption is that urban massing describes a swarm-formation of many buildings. These buildings form a continuously changing field, whereby lawful continuities cohere this manifold of buildings. Parametric urbanism implies that the systematic modulation of the buildings’ morphologies produces powerful urban effects and facilitates field orientation. Parametric Urbanism might involve parametric accentuation, parametric figuration, and parametric responsiveness”40_.

Parametricism is still in its early development and subject of many authors’ criticisms, mainly for its elevation to new style in architecture. “The styles are a lie” said Le Corbusier, claiming architects do not design in styles, but just follow trends and beliefs of the time. Styles are something history will decide upon. Still Schumacher and the ZHA are recognized as one of the most important and active practice using and researching with parametric, besides the theoretical criticisms. A relevant project, one of the most famous, from the ZHA firm is the Kartal Pendik

40. Ibid.

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Masterplan in Istanbul, Turkey, winning competition project in 2006. The site is a 55 hectares abandoned industrial area located between the two regions Kartal and Pendik.

Main goal is to reduce pressure on the city’s historic core and moreover to create a new centrality for the city, comprising all programmatic components of a city, at the confluence of major infrastructure connecting Istanbul and other European and Asian countries. The site was a blank slate, needed to be populated with many different functions, and allowing ZHA to utilize parametrics through the entire design process, both for street network and building design.

Starting point for the project was the existing urban infrastructure, incorporated in

Exploring Parametric Design to propose an Urban Development Plan located in Sydney