The nature of cities as concentrators of people, resources and economic opportunity, as well as associated negative socio-economic and environmental impacts, presents an imperative for urban governments to shape their cities in order to maximize economic opportunity and social welfare for its residents, while limiting negative environmental impacts. This is often voiced in aspirations of a ‘sustainable city.' Urban metabolism provides a unique conceptual approach for understanding urban resource dynamics shaping sustainable infrastructure systems (Brunner 2007; Kennedy et al. 2011).
The scale of analysis for urban metabolism studies is typically presented at aggregate city-level, suggesting that the urban metabolism is homogeneous across populations within a city. However, in reality this is not the case, and it is difficult to prescribe effective pathways towards shaping a sustainable city when different parts of the city have completely different functional dynamics. Currie and Musango (2016) concludes with a call for shifting away from single quantification of entire cities, and highlighting the inequities of resource access, as well as the intensity, form and cost of resource flow in different areas. Establishing a framework to examine metabolism of representative household types across the city would facilitate and inform policy interventions within specific city areas, which contribute to the overall sustainability: this is termed as differential urban metabolism in this project.
The differences in function and form between various areas in cities of the global south are particularly visible as inequality defines and shapes much of the urban landscape and resource flows. Stated political agendas aim either to undo legacies of differential resource provision (via colonial, capitalist or apartheid mechanisms) or to increase standards of living and associated economic participation in under-developed areas through improved resource availability and utilisation. However, the degree to which resources are available, accessible and deliverable is typically not measured. In contexts in which we expect a rapidly growing middle class, and in which upgrading of informal settlements is legally mandated, this project asks what the resource consequences would be of upgrading all of Cape Town's informal settlements (an estimated 140 000 households) to a sufficient level of resource consumption (which offers quality of life).