Quantifying Quality: Numerical Representations of Subjective Perceptions of Urban Space

The quality of urban space influences the sustainability of cities and the well-being of their inhabitants, but quantifying this attribute through numerical representations of urban conditions has proved difficult in urban planning. This article describes how integrating qualitative and quantitative datasets through analytical and generative methods can enhance the comprehension and evaluation of urban space quality. Focusing on the city of Sydney, Australia, the research employed a public survey to assess the urban conditions of 11 suburbs against key qualitative traits of beauty, comfort, safety and ambience. The data was analysed using image segmentation and geographical information systems, and correlations between the survey responses and the urban characteristics present in each image were calculated. The results include nine characteristics of urban spaces that reflect the listed qualitative traits and a percentile ratio for each urban condition that represents the perception of each trait, offering a comprehensive understanding of the determinants of the quality of urban spaces. The research contributes to ongoing efforts to improve the quality of life in urban environments by providing a highly specific and clear quantification of four highly subjective perceptions of urban space. The proposed quality measurement method represents a valuable tool for policymakers, urban planners and designers to use to inform decision-making and ultimately create more liveable, sustainable and inclusive cities.