Informal urbanism has been generally studied within social, econmic and political frameworks, yet little is known of how it performs in terms of urban vitality. The aim of this article is to better understand the urban vitality of informal settlements and how they can be improved by using a combined morphological approach that encompasses street-network accessibility, building density, land use diversity and transformability index. This study focuses on the city of Cairo, which has experienced rapid urban growth over the last seven decades. Much of this growth has concentrated in informal settlements on the outskirts of the metropolis. Taking Manshiet Nasser district as a case, we measured the degree of urban vitality of the area through a combination of Space Syntax, Spacematrix, and the Mixed Use Index (MXI). Informed by a transformability index (TI), the results can be used as part of the design process to (re)develop unattractive areas. The findings show that this combined approach works as a diagnostic tool for detecting development potential and, therefore, underpins the identification of cost-effective ways of intervention, for enhancing vibrant urban environments.

Identifying the economic potential of informal urban areas is a topic of increasing interest for policymakers and practitioners in less developed countries, yet little is known of how informal street design influences the type and count of business opportunities. By adapting a space syntax framework, this study aims to quantitatively verify the association between the street design of informal areas in Cairo and patterns of home-based businesses in areas where small business prevalence is high. This paper contributes to the literature by developing a methodology which is fit for testing hypotheses, allows to control for the influence of unobserved factors, and which extracts the spatial rules, trends or logics of business patterns. The results show that street accessibility is an important factor in encouraging (or discouraging) the settlement of home-based businesses. Home-based businesses are spatially distributed along the local primary streets, which provide flows of potential customers. Our findings contribute to a better knowledge base for understanding how different types of economic activities and the spatial properties of the built environment relate to each other, how street design may impact on the emergence of small and micro-enterprises, what kind of business may suit isolated laneways, how informal business activities can be anticipated and managed, and how land use regulations can be improved.