35 DIDÁCTICA Y CURRÍCULO Geometry, Design and Construction: A Parametric Model for Non-standard Timber Construction

ABSTRACT Architectural design is confronted with a renewal of formal vocabulary regarding the advancements in computational techniques. Recent advancements in digital representation and geometric description of architectural form are raising more and more questions concerning materialization. Construction and assembling constraints are parts of the data needed to rationalize a geometric model. This paper offers a report on part of a research project aimed at elaborating a tool capable of transforming geometric descriptions of non-standard forms to constructive geometry. KEYWORDS: digital fabrication, materialization, parametric modeling, timber construction, digital design tool. Design and Construction Architectural design is confronted with a renewal of formal vocabulary regarding the advancements of digital design tools. However, the capacity of representing and modeling more and more complex geometries (curves, surfaces, etc.) has been the principal driving objective of the development of many of these design tools. While the first generations of such tools were capable of representing and managing basic geometric elements such as points, lines and Euclidean space, recently developed modeling systems offer the possibility of representing and manipulating advanced geometries and higher dimensional spaces (NURBs, complex curvature, etc). Although they provide the possibility of modeling non-standard complex morphologies, design oriented tools tend to restrict the final design to a geometric configuration. The tradition of architectural design has for long time prioritized the generation of form over its materialization. Materialization and production become important issues only once the design process is complete. The introduction of CAD-based tools forces architects to work on two-and three-dimensional geometric representations. This restrictive quality of digital geometric modeling -as explained above-somehow enriches this situation. The family of non-standard morphology is transforming into a utopian universe of non-constructible virtual objects. "If architects don't try to feed material constraints into software, they become moviemakers or image manipulators instead of designers who actually construct things" (Zaero-polo, 2004, 98). The recent generation of computational assistance to the process of architectural design such as associative computer aided design and manufacturing technologies is based on establishing a flow of information between the design and production stages. In such a context, the issue is to make a link between geometric data and the material characteristics of the final design. This begs the question, how can one enrich the geometric model so that it can support the post-design phases. This paper reports on the elaboration of a parametric model aimed at adding a semantic layer to a geometric model, specifically in the field of timber construction. The parametric model is then used to develop a tool capable of generating the structural volume of a non-standard surface, based on a specific timber construction system. The parametric model is supposed to integrate materiality based on classified timber construction methods with the objective being to provide the data needed for production phases