Parametric Design

The architectural design process is almost always iterative. Designers create solutions that, in turn, pose new questions, which are then investigated to generate more refined or even entirely new solutions. Designers often use computer aided tools to build models and help them visualize ideas.

However, the vast majority of these models are still built in such a way that they are difficult to modify interactively. The problem becomes more severe when bespoke 3D models are geometrically complex. Changing one aspect of such a model usually requires extensive low-level modifications to many of its other parts. To address this problem, designers have begun using parametric design software, which allows them to specify relationships among various parameters of their design model. The advantage of such an approach is that a designer can then change only a few parameters and the remainder of the model can react and update accordingly. These derivative changes are handled by the software, but are based on associative rules set by the designer.

Associative and parametric geometry, in essence, describe the logic and intent of such design proposals rather than just the form of the proposal itself. This kind of design both requires and helps to create powerful interactive tools that allow designers to explore and optimize a multitude of possibilities while reducing the amount of time it takes to do so in a rigorous manner. Engaging these parametric and algorithmic processes requires a fundamental mindset shift from a process of manipulating design representations to that of encoding design intent using systematic logic.

Algorithmic thinking calls for a shift of focus from achieving a high fidelity in the representation of the appearance of a design to that of achieving a high fidelity in the representation of its internal logic. The advantage of algorithmic thinking is that it can build ‘… consistency, structure, coherence, traceability and intelligence into computerized 3D form’.1 Parametrically and algorithmically built models can react with high fidelity to their real-life counterparts when subjected not only to user changes of geometric parameters, but also to structural forces, material behavior and thermal and lighting variations, as well as contextual conditions. Because they accurately represent the internal construction logic of the structure at hand, parametric models can also be unfolded or translated into geometries that can be digitally fabricated.

This powerful digital workflow of parametric form finding that is influenced by design intentions as well as performance analysis and digital fabrication logic is one of the defining characteristics of current digital architectural practice. Contemporary architects, such as Patrik Schumacher, partner at Zaha Hadid Architects, have gone as far as coining parametricism as the name of a new movement in architecture following modernism. He writes: ‘We must pursue the parametric design paradigm all the way, penetrating into all corners of the discipline. Systematic, adaptive variation and continuous differentiation (rather than mere variety) concern all architectural design tasks from urbanism to the level of tectonic detail. This implies total fluidity on all scales.’2 He points out that
the fundamental themes in parametric design include versioning, iteration, mass-customization and continuous differentiation. It is helpful to briefly define these terms.