Isovist Analysis, Theories and Methods

Abstract

Isovist analysis offers a way of geometrically describing the spaces and forms of a building which can be seen from a particular position. As such, it combines a consideration of both fixed, building-related factors, such as space and form, and temporal, experiential ones, such as visibility and the impact of movement. Isovists are part of a larger field of study known as visibility analysis, which is concerned with quantifying the relationship between vision and behaviour. As the previous chapters have demonstrated, several of the Space Syntax methods connect human vision to spatial cognition and intelligibility, that is, the capacity to understand and then navigate through a building. It will also be remembered that convex maps comprise the set of visually defined zones, and axial maps represent an optimal system of movement and surveillance paths in a building or city. In both of these methods, the visual properties of space are highly generalised or abstracted. In contrast, isovists have the potential to mimic, and thereby be used to examine, the visual experience of a building from a particular point in space, and even take into consideration specific human features such as eye height and stride length while moving. In a sense, this technique begins to model the way space is perceived and experienced, whereas the earlier methods were concerned with spatial structure, hierarchy, permeability and intelligibility. In combination, all of these factors-the social, cognitive and perceptual-are at the core of arguments that historians, critics and architects use to explain the successes and failures of Modernism.