PARAMETRIC DESIGN: AN APPROACH TO GENERATIVE FORM IN ARCHITECTURE
Since the Industrial Revolution, technological development has always been the main inspiration for architects. With the considerable improvement of informative tools in recent years, the architects and designers have experienced radical changes in design methods, especially the application of computational design. This paper focuses on parametric design, an upcoming design tool, during the design process in contemporary architecture. Despite undeniable advantages of this tool in design process, we will reevaluate parametric design in the design workflow as well as the role of the designers. Investigating the parametric design process reveals its role in some recent buildings and inspires continued interest in generative forms for future concepts.
In recent years, it has been an increasing interest in applying computer aided (CAD) methods in the architectural design process. Consequently, there is a variety of design software available in the market. It is clear that computers can analyze complex structural systems and support to complete tender drawings. However, there is limited progress in the digital applications complementing the conceptual design to generate building forms. One of the latest trendy tools is parametric design, defined as an approach to generative forms in the contemporary architecture.
The term “parametric design", also known as “associative geometry” (Burry and Murray, 1997) “relational modeling”, “variational design” or “constraint based design” (Mender, 2001), implies the representation of a design with a series of associative operations, controlled by constraints and parameters. Parametric design is a method of intelligently designing architectural objects. These are defined in parametric software and able to generate interactive forms in the three dimensional (3D) space. However, it should be noted that there is not a clear boundary between a parametric design tool and other computer-aided drafting and modeling software. In other words, forms can be created with basic parameters in currently called computer aided programs. In these cases, current CAD systems allow architects to modify the primitive properties. However, this does not work in complex structures in which architects modify parts separately.
With the use of parametric design tools, architects can study the interactive relationships of architectural objects in the early steps. Furthermore, they can revise basic aspects of the actual construction, including material, manufacturing technologies and structural components. In the other hands, these new digital tools are challenging architects in practicing architecture.
Parametric design has been applied in several world leading architectural companies, including Zaha Hadid or Frank O'Gerry. Although they have been given many critical comments for the extraordinary, innovative forms breaking the regular urban context, the architectural community must accept that parametric design or parametricism is the coming trend in the next decade. Shapes of their designs are refreshed and generative without requirements for overwhelmed workforce spent in manual processes. It can be assumed that parametric design tools concern not only about acceleration and variation, but also precision and optimization of the design process. Finally, such tools translate also complicated data into rational and simple orders.
Conversely, this trend toward complexity leads to other crucial design problems. It requires the changes in architectural training of academic institutes with deeper and broader knowledge of algorithm and computer software. Learning and practicing architecture become more and more complex. The architects must not forget that they are the master and control the tools, rather than a modern workslave for scripting parametric design tools.
The aim of this paper is to investigate parametric design as an approach to generate forms in some contemporary buildings. In this paper, we will identify the conceptual elements defining parametric design tasks and illustrate how these elements are transformed during the design process. Recent research in parametric design mostly focused on the mathematical and engineering problems. However, this report will give illustrations for parametric tools during practice, especially the conceptual formulation in architectural design.
Architectural design, like the overall process of development, proceeds through a series of distinct phases. The entire design process is rather complex, thus requiring the cross-disciplinary workflow from the conceptual phase to the constructional phase, with the close collaboration between the architects and the engineers. The design phases are defined in The American Institute of Architects' Document B163 - "Standard Form of Agreement between Owner and Architect for Designated Services 1993 Edition”. Understanding these phases is good way to evaluate the assistance of parametric design in the whole design process. These design phases can be separated in different steps: Pre-Design Phase, Site Analysis Phase, Schematic Design Phase and Design Development Phase, in which the size and character of a project are refined and described; the Contract Phase and the Post-Contract Phase, in which assistance in an owner's use and occupancy of a project is provided.
The early phase of design is the most crucial part of the entire process, especially the schematic design. During this design phase, the architects create a set of possible solutions. The output of this conceptual phase can lead to fundamental inputs for further steps. The architects and designers with graphite design tools can also develop generative forms during the conceptual phase. But the forms are constrained in the two-dimensional (2D) diagrams with weak connections between all pre-design data. The architects must distribute more time for manual works, such as making models or drawings revisions. On the other hand, parametric design allows the architects to evaluate all alternative solutions in both 2D and 3D diagrams, and then find out the suitable proposals for clients. Even if their clients require further modifications or revisions, they can alter all parametric factors without repeating the entire process from the beginning. This is the main advantage to distinguish the parametric design tools with the classic graphite design tools, such as hand sketches or models.
In addition to these main advantages, parametric design tools enable architects to approach generative forms. In other words, in parametric design, it is the elements of a particular design that are clarified, not its shape. Hence, different generative forms can be created by modifying some specific values to the parameters. We have abilities to experience all possibilities of the imagination. Furthermore, these tools also have valuable contributions to the iterative design refinement, in the overall translation from ideas to construction documents. We will revisit some recent projects to evaluate how parametric design might have been significant assistance to the architects.
FORM GENERATION METHODS
In the domain of architecture, since design is an issue of organizing and responding to a set of relations, parameters are always essential constituents in that process. The parameters include a variety of factors, including sun altitude angles, climatic data, structural limits or acoustic pre-requisites. These equally essential aspects must be calculated in association to each other. For that reason, we need a comprehensive analysis to clarify the application of parametric design in contemporary buildings.
To detect the design methods, the abstract generic form of every building is analyzed to basic two-dimensional shapes and the transformations applied to these shapes as well as the connection between them was required. Common methods are based on repetition and the transformation modifiers following each repeating step. The Cartesian coordinate system is the examined coordinate system . The physical ground is represented by the surface created by the X- and Y- axes, while the Z-axis is perpendicular to the surface generated by the two axes. Basic transformation modifiers are applied to the primitive. These modifying functions include movement, rotation and scaling, as well as taper or twist as highly complex modifiers.
BMW Welt, designed by COOP HIMMELB (L) AU in Munich, is the first examined case. The main component of the building is analysed to a closed spline on the XY-plane, which is running up around the vertical-circulation axis, then connecting with the upper floor. The main structural body is formulated by triangular modules, a standard module for freeform structures. A vertical extrusion and taper transformations are applied on the base shape of this component in order to transform it to a 3D object. Due to the application of parametric design tools, architects developed the preliminary concepts, converted the basic model to the computational model, and then produced data for construction, with accurate calculation from the early steps.
A similar case is Beijing National Stadium by Herzog & de Meuron in Beijing, China. Inspired by Chinese art and culture, the "Bird's nest" has a simple structure, while the final geometry is very complex. The main elements support each other and converge into a grid formation, embracing the philosophy of balance and harmony. The architect created the original shape resembled a Chinese lantern, rebuilt it to be a three-dimensional model, and then translated data into basic scripting. With these basic inputs, the design group developed alternative forms for the future stadium; then, with the computational tool, they also reduced the repetitive work during various experiments.
The advantages of parametric design in these projects are to plan and synthesize the overall requirements and relationships of many design elements into one form. In other words, it can synchronize building forms with the architectural and structural criteria. It not only explores all potential generative forms, but also suggests construction methods to distribute the final concepts. These three dimensional models in computers can be exported to two dimensional data, as well as the material and technical specifications.
Furthermore, by the uses of latest CAD/CAM printing machines, the architects can transform these 3D models into real building models, as a classic method for architects to evaluate the final proposals. As a matter of fact, in the studio of Herzog & de Meuron, they have mocked up the real-sized details for the final evaluation. Obviously, it demonstrates these generative forms created by digital tools liable for construction in real life.
On the other hand, recent architectural debates are concerned about the integration of digital tools during the design process. Most of critical questions concentrate on these topics: whether these parametric design tools are means or masters; how the role of designers and the design vision change in coming years, while the architects and designers spend most of their time in scripting and modifying technical parameters; and whether they move too far from the architectural field to the technical region. Other worries also wonder if these generative forms support the human life ,or conversely, human beings must adapt to those futuristic habitats.
However, they all agree that architecture is in the mid-point of an ongoing cycle of adaptation - retooling the discipline and adapting the architectural and urban environment to the mass-consumption era. Till this moment, those worries above are overestimated. The application of parametric design tools grows dramatically, as some recent articles consider this style as parametricism, the great new style after modernism. The architectural community also encourages the movement from the classic graphite design to the digital-age design, for aesthetic effects, as well as the economic efficiency. The most pioneer architects in parametric design debate: even the final product drives directly from the automatic processing, the original concept must be created by designers. No matter how these computational tools change the design work, designers' mind is always the milestones to formulate design concepts.
In conclusion, the advantages of parametric design tools are undeniable. Reinvestigating the working methods in some recent projects illustrates the role of these tools in the design workflow. It can be noted that new digital tools can be used to produce not only the better performance design but also generative and dynamic concepts. However, the debate between the classic graphite and the digital-tool applied designers ones will endlessly continue. The questions are not only about how to balance the concepts in the relation with the social and spatial data, but also the role of designers in the form generation process, whether the architects are dependent or independent on the automatic machines. We are not dealing directly with architectural practice but, rather, with instruments that may help to improve architectural practice through improved educational methods (Monedero, 1998). It requires further study not only in practical cases, but also technical features and underlying architectural theories relating to generative forms.
Burry, M. and Murray, Z.: 1997, Architectural Design Based on Parametric Variation and Associative Geometry, eCAADe97, Vienna.
Kolarevic, B.: 2001, Designing and Manufacturing Architecture in the Digital Age, eCAADe01, Helsinki.
Burry, Mark: 2002, “Blurring the lines: an exploration of current CADCAM techniques, parametric design and rapid prototyping - mediating between analogue and digital skill sets”. Architectural Design, no. 73, vol. 2, Mar.-Apr., 2003, pp. 110-118
Mitchell, W.J.:2001, Roll Over Euclid: How Frank Gehry Designs and Builds, in J. F. Ragheb (ed), Frank Gehry, Architect, The Guggenheim Publications, New York, pp. 352-363.
Monedero :1998, The Role of the Architect in the Age of Automatic Reproduction, eCAADe 98, Paris.
The American Institute of Architects: Document B163 - "Standard Form of Agreement between Owner and Architect for Designated Services 1993 Edition”
Patrik Schumacher, London:2008, Parametricism - A New Global Style for Architecture and Urban Design
Published in: AD Architectural Design - Digital Cities, Vol 79, No 4, July/August 2009.