Validating a Sustainable, Smart, and Circular City Architecture Through Urban Living Lab Experiments

Rapid urbanization and climate change pressure cities to integrate sustainability, digitalization, and circular economy principles. Yet most existing approaches treat these agendas separately, leaving gaps in how urban infrastructures, governance, and data systems can jointly support circular transformations. This paper addresses this challenge by proposing and validating a Sustainable, Smart, and Circular City (SSCC) architecture that operationalizes the waste–energy–information nexus. The architecture is structured into seven interconnected layers—Physical, Digital, Analytical, Participatory Governance, Data Strategy, Innovation Management, and Assessment—and is tested through two integrated experiments in the Fenicia Urban Living Lab, Bogotá: (i) an AI- and drone-based system for waste detection and community reporting and (ii) a solar-powered IoT urban garden for environmental monitoring. These experiments demonstrate how digital twins, participatory governance, and multi-actor collaboration can activate circular strategies while enabling evaluation against international standards (ISO 37106, U4SSC, LEED). The results confirm that the SSCC model can transform siloed services into integrated, circular functions that enhance quality of life, productivity, and ICT-based sustainability. The originality of this study lies in validating an SSCC architecture that incorporates the waste–energy–information nexus across seven layers and demonstrates, through Urban Living Lab experimentation, how such an architecture can guide the transition from Smart Sustainable Cities to Circular Cities.