Gideon Aschwanden

Digital Urban Modeling and Simulation

In the global context, the population of cities and urbanized areas has developed from a minority to become the majority. Now cities are the largest, most complex and most dynamic man-made systems. They are vibrant centres of cultural life and engines that drive local and global economies. Yet, contemporary urbanized areas are environmentally, socially and economically unsustainable entities laying increasing pressure on the surrounding rural areas. Traditional methods of planning and managing large cities that lead to this situation have reached their limits. The planning and design processes therefore need a radical re-thinking. On the computational side, this necessitates the integration of new methods and instruments. On the planning and design side, this requires the involvement of stakeholders and decision makers much earlier than normally done in the past. The combination of interactive design and computation will demonstrate the effects and side effects of urban-rural planning or re-development. We build our design research approach on dynamics and scale: viewing cities and settlements as entities with dynamic urban metabolisms, we propose to apply stocks and flows simulations to the building scale (small, S-Scale), to the urban scale (medium, M-Scale), and to the territorial scale (large, L-Scale). Our long-term goal is the sustainable urban-rural system. Planning and implementation examples from Switzerland and ETH Zurich Science City serve as test cases, with the intent to use the findings for developments in other parts of the world.

Limits of space syntax for urban design: Axiality, scale and sinuosity

Space syntax analysis of the city as a movement economy has made major contributions to our understanding of the spatial structure of cities, particularly the importance of a mapping of network integration in relation to density, functional mix and streetlife vitality. It has focused attention of urban researchers onto the importance of the relations between the sociality and spatiality of the city. The primary methods of syntactic analysis involve a reduction of urban morphology to a set of spatial axes; here, we explore some limits to such analysis for urban design. Topological analysis of axial models has long recognized problems in accounting for distance, scale and sinuous streetscapes. Existing adaptations to axial methods that address such problems are modelled and shown to produce a broad range of results for the same urban morphology. In each case, we also compare different capacities for to-movement and through-movement – the distinction between ‘closeness centrality’ and ‘betweenness centrality’ that shows that network integration is multiple. We argue that axial analyses privilege visibility over accessibility and can produce distorted mapping at walkable scales; only one of the methods tested measures permeability and walkable access. Space syntax analysis is a powerful tool that will be more useful the better such limits are understood.

BIM-PIM-CIM: The Challenges of Modelling Urban Design Behaviours Between Building and City Scales

This paper discusses the challenges that designers face when modelling the anticipated behaviours of people: their movement and transactions around and within precinct scale development. Building Information Modelling (BIM) software philosophy contrasts with that of City Information Modelling (CIM)—the route by which we consider how precinct scale development, being somewhere between the two (BIM and CIM), requires a wholly different approach to information and behaviour modelling. The authors offer evidence of the value of augmenting the planners’ analytical approach with the architects’ synthesis from data leading to meaningful speculations on otherwise unanticipated future scenarios for the precinct far beyond expectation. Novel approaches to modelling behaviour at precinct scale suggest alternative readings of precincts, which require a wider set of approaches to Precinct Information Modelling (PIM) software development than simply an expansion of BIM.