Decarbonisation in the construction sector, consisting of a process based on the abandonment of fossil resources and the achievement of greater resource efficiency, is increasing in both new construction and renovation. The concept of circularity is seen as a strategy to reach this goal. The direct environmental impact of building designs can be quantitatively evaluated by assessing total mass, embodied energy, and embodied CO₂ in combination with circularity criteria, such as design for disassembly, materials and product origin, as well as recovering potential. This paper presents a method for easily assessing these parameters, thus obtaining a Building Circularity Indicator. To validate the method, its application in a pilot case of a manor villa located in Argelato (Bologna, Italy) is provided in the framework of the European Horizon 2020 project “DRIVE 0—Driving decarbonization of the EU building stock by enhancing a consumer-centred and locally based circular renovation process”. The deep renovation intervention developed is aimed at increasing energy performance by pursuing a circular approach that has rarely been tackled in protected heritage. Furthermore, the benefits of a circular versus a linear strategy are demonstrated through an LCA as well as LCC analyses assessing the environmental and economic impact of the intervention. The research results validate the proposed method as a tool to support operators in the construction sector.

The environmental and economic evaluation of energy renovation in buildings plays a crucial role in achieving sustainability goals and the decarbonization of the built environment. This paper presents a case study of a student house in Athens, Greece, to assess the environmental and economic impacts of energy renovation and seismic reinforcement with a steel exoskeleton. This study utilizes a comprehensive approach that combines life cycle assessment (LCA) and life cycle costing (LCC) methodologies using One Click LCA. The LCA assesses the environmental impacts associated with energy consumption and greenhouse gas emissions, while the LCC evaluates the economic aspects, both analyses being conducted for a lifespan of 25 years from now. The results provide an evaluation of what would happen in terms of greenhouse emissions and costs in two scenarios: with and without interventions. ProGETonE strategy results in an environmental impact with a GWP of 26.78 kgCO₂eq/m²y with a reduction of 30% of the pre-renovation state. Economically, the actualized energy use costs for 25 years are 50% less in the post-renovation state, but the high construction costs make the strategy seem inconvenient. In this context, it is important to consider the non-economic benefits of seismic reinforcement, such as enhanced safety and the potential lives saved, which are critical in high seismic zones. These advantages complement the strategy’s environmental and energy use impacts, underscoring the holistic value of integrated seismic and energy retrofitting approaches like ProGETonE. The study underscores the importance of LCA and LCC analyses when evaluating the feasibility of renovation projects and of an evidence-based decision-making process for policymakers, building owners, and stakeholders for energy-efficient retrofitting.