There is an evident relationship between climate change and the building sector through reciprocal environmental impacts. The circular economy is fitted into this relationship as a mitigation strategy in the building sector, thanks to its nature of life cycle perspective consideration, support for stakeholder collaboration, and the ideology of waste minimization, reduction of natural resource consumption, and greenhouse gas emissions. This article aims to conduct two subsequential systematic literature reviews to evaluate the status in the scientific literature about the circular economy as a climate change mitigation strategy in the building sector and to find the place taken in the scientific literature about the stakeholder’s involvement toward circularity transition in the abovementioned link. As a result of the methodological approach, publicly available and reliable publications have been identified and analyzed based on the publication year and territory. The results indicate an increasing scientific literature contribution about the context, but the stakeholder concept is considerably taken less place; thus, it is a gap in the scientific literature. The stakeholder focal point, which the innovativeness of this article lays down, needs more attention in academic research, thus in the sector with the strengthening collaboration and mutual awareness among stakeholders.

The building reuse can reduce both consumption of non-renewable resources and production of construction and demolition waste, preserving the architectural and constructive culture. The progressive depopulation of the European inner areas is an opportunity to discuss the potential of reuse and sustainable adaptation of extensive heritage sites to cope with abandonment processes. The study of depopulation processes, as well as the investigation of case studies, allows to analyze the main strategies implemented to regenerate and repopulate abandoned inner areas, to highlight successful approaches and intervention criteria. In this scenario, “smart shrinkage” emerges as a powerful strategy to systemize resources and values embedded in the territories. On the basis of the economic-territorial interpretation of the performance decay process of buildings and settlement systems, developed by the research group of the Universities of Sassari and Catania, the paper proposes a multi-scale methodological approach for the evaluation of enhancement strategies and technological upcycling. The research links building performance with the urban and territorial values, integrating the Performance-Based Building Design in an axiological approach based on the solidarity between functions and values, referring to the economic category of human and urban capital. The model is tailored to the characteristics of Sardinia, the Italian region with the strongest population shrinkage in inner areas. The result is an analysis-evaluation-programming model, based on an iterative process of information/decision-making, allowing to steer intervention strategies toward a balance between the rehabilitation of the built environment and the enhancement of cultural and environmental resources, offering new opportunities for socioeconomic development.