Designing a Smithsonian Roof
Using the set-out geometry and a set of parameter values, a computer script creates a variety of detailed roof components. The script adapts each component to its local condition and, through a performance evaluation, the components respond to their environment.
[an error occurred while processing this directive]
The use of scripting as a design approach provided many benefits:
1. The simultaneous generation of multiple representations within a single model; a center-line model for structural analysis; a triangulated flat-panel model for acoustic analysis; a simplified model for hidden line visualizations; lighting node position models; node and beam set-out drawings and spreadsheets; unfolded beams for the digital fabrication of scale models; and a complete model of all roof elements for the creation of drawings by the project team.
2. The independent development of roof configuration and individual component strategies. The roof geometry was free to change without affecting the logic of the beam section or panelization system. Within the script, different modules of code could be inserted, removed or edited to create new roof options.
Using this approach, the long-chain dependencies of a fully associative system did not exist, and modification was simpler and regeneration much faster. When changes were made to the script or to the set-out geometry, a new digital model could be generated rapidly. A dynamically parametric model was not necessary.
3. A computer-generated model gave very precise control over the values and relationships within the roof system. It produced consistent and repeatable results where the design history was saved as a copy of the generating script and the set-out geometry used.
The design evolution involved the use of many different media and techniques and an intense dialogue between a large team and many consultants. The script became a synthesis of all the design ideas and was constantly modified and adapted during the design process.
Scripting was used as a sketching tool to test new ideas. This explorative approach required knowledge of both programming and architectural design combined with interpretative skills on many levels.
It proved a fast and flexible approach. The final version of this generating code was 5,000 lines in length and had 57 parameters — some numeric values and others switch-controlling options. Using only the set-out geometry as input, the script generated approximately 120,000 elements in about 15 seconds; 415 models were generated over six months.
It is possible to generate thousands of different options by using scripting. It therefore becomes increasingly important to not only understand the system constraints, but to have a clear strategy for evaluating the generated options. The design was evaluated by many methods: structural, environmental, acoustic and aesthetic.
While there was no attempt to automate the feedback process, it did prove beneficial to work closely with consultants to better understand their data-input needs for their analyses. By building the production of this information into the script, the generation/ analysis cycle could be shortened.
Working closely with the structural engineers, Buro Happold, reduced the time taken for the generation/ analysis loop.
As well as creating traditional visualizations and animations, a new technique was employed in which an image set was automatically generated and reviewed for a matrix of options.
In parallel, the physical production of digitally fabricated scale models and the production of 1:1 mock-ups was critical to the decision-making process.
Discuss this article in the Architecture Forum...
Achim Menges is an architect, professor, and director of the Institute for Computational Design at Stuttgart University's Faculty of Architecture and Urban Planning. Currently he also is visiting professor at the Harvard Graduate School of Design and visiting professor for the Emergent Technologies and Design Graduate Program at the Architectural Association in London. He previously taught at the AA School of Architecture as studio master of the EmTech program and as unit master of Diploma Unit 4, and has also taught at the HfG Offenbach University for Art and Design in Germany.
This article is excerpted from the March/ April 2006 issue of Architectural Design (Volume 76, Issue 2, "Instrumental Geometry" by Achim Menges), with permission of the publisher, John Wiley & Sons.