QUANTIFYING THE QUALITATIVE : an evaluation of urban ambience 134

Delightful urban ambience is an important indicator of liveability; in turn liveability is a significant aspect of sustainability. But can this quality be quantified? To the extent that ambience reflects the (measurable) configuration of urban form; it is proposed that the comparative expression of certain ambient qualities can be evaluated between areas of differing morphology. Ambience may be conceptualised in terms of the properties of and relations among the distinct sets of elements, from building materials to city blocks, which comprise any given urban structural unit (USU), a construct prefaced on the morphological differentiability of urban form. This paper introduces the derivation of the USU and outlines the results of combining approaches derived from space syntax and fractal geometry to investigate three significant ambient properties – permeability, legibility and diversity – for three dissimilar USUs in Sydney, Australia. It concludes with a brief exposition of a method to test these results against user judgements, which are assumed to reflect the integration of perceptual cues from the environment.