The Process of Digitalization of the Urban Environment for the Development of Sustainable and Circular Cities: A Case Study of Bologna, Italy

The residential heritage that was built during the great expansion of real estate after the Second World War has severe deficiencies in structural safety, fire resistance, energy efficiency, and accessibility and these cannot be solved with sustainable renovation measures. This study focuses on replacement interventions and promotes a management model that addresses three areas (technical, social, and economic) and it refers to the application of the circularity principle to the construction sector for the goal of climate neutrality by 2050. The final objective is to define a protocol—namely, the guidelines—to reference in a decision-making process that promotes urban regeneration by comparing demolition with reconstruction and renovation. The proposed methodology allows for the determination of suitable areas in Bologna for replacement and the joining of the municipal geodatabase with data from archival research on building permits in 1949–1965 by using GIS software. This digital archive can be implemented in a digital twin for an urban block, which can become a predictive tool for urban planning and the management of the whole life of a building. The main result is the characterization of urban blocks by identifying typical features belonging to specific building libraries that are validated with density analyses. These urban clusters and building archetypes can be used to assess targeted intervention measures by using specific tools, such as predictive maps and 3D city models.