Urban governance to support adaptable solutions for conversion of residual street spaces into social spaces.

Abandoned residual street spaces, frequently marginalised in formal urban planning frameworks, represent a significant yet unrealised resource for enhancing urban liveability, especially within the complexities of dense historic urban neighbourhoods. This study investigates how such underutilised spaces can be strategically transformed into vibrant social hubs. Focusing on the Castello neighbourhood in the historic centre of Cagliari, Italy, the research adopts a unique mixed-methods approach grounded in a sequential exploratory design. It begins with spatial analysis using space syntax techniques, including segment analysis, axial analysis, and visibility graph analysis, followed by GIS-based land use mapping and field-based qualitative assessments to identify and prioritise residual spaces based on their social potential. The findings highlight several high-potential sites characterised by pronounced spatial configuration and contextual qualities, suggesting practical insights into the design and governance of adaptive social spaces. The original contribution of this study lies in its incorporated and replicable methodological framework that combines quantitative spatial analysis with qualitative urban evaluation. The results not only advance the theoretical discourse on residual urban space but also provide pragmatic strategies for inclusive urban regeneration. The proposed framework is applicable across diverse urban contexts, offering a scalable model for cities aiming to enhance sociability through the adaptive reuse of neglected urban fragments.