The increase in global surface temperatures will surpass the 2 °C target set by the Paris Agreement unless carbon emissions are lowered to zero by 2050. To date, the building sector is responsible for 38% of all carbon emissions, thus one of the main targets is represented by the development of building strategies that can facilitate the transition toward carbon-neutral buildings. The main strategies are today represented by nearly zero energy buildings (nZEBs), zero energy buildings (ZEBs)/net zero energy buildings (NZEBs) and net zero carbon buildings (NZCBs). Particularly, NZCBs completely target zero operational and embodied carbon during their life cycles, fulfilling the leadership role in the decarbonization of the construction sector. Moreover, adopting the European Standard EN 15978:2011, carbon emissions can be precisely classified to enhance strategies aimed at reducing them. Commercial viability remains a fundamental economic driver, but the higher initial capital costs hinder the NZCBs. In addition, legislative, socio-cultural, technological, professional and geographical barriers hold back its diffusion. NZCBs can be met by a four-steps program: embodied carbon reduction, operational carbon reduction, increase in renewable energy supply and offset and carbon storage. Circular economy principles are strictly connected to design for disassembly and for adaptability to reduce embodied carbon, while passive design and solar and geothermal energy production can satisfy the renewable energy demand of the building. The aim of this narrative review is to determine and describe which is the current state of the art for NZCB definition, the drivers and barriers toward its application in a broader context and which strategies are eligible to meet the ambitious goal of zero operational and zero embodied carbon emissions.

The building sector accounts for 38% of carbon emissions, the principal cause of climate change. To meet the targets set by the Paris Agreement, including zero net emissions by 2050, it is necessary that governments develop a culture of sustainability. Whole Life Carbon Assessment of a building, comprehensive of operational and embodied carbon (EC), is described by EN15978:2011. Net Zero Carbon Buildings (NZCB) achieve a balance of zero emissions during their life cycle, promoting both reduction and compensation by adopting many strategies (e.g., reuse of existing structures, design for adaptability and disassembly, circular economy principles). Choosing bio-based materials is also helpful to compensate for EC, thanks to the biogenic carbon stored during their growth. The aim of this research is to find out which strategies are relevant to meet NZCB target, in order to apply them to a case study of reuse of an abandoned building in Milan, highlighting the design process. Material quantities were extracted from the BIM model and imported in OneClick LCA to assess embodied carbon emissions (A1–A5 modules, material production and supply, transport, construction). The final design stage achieved a reduction of 91% in EC compared to a standard new construction, while the bio-based materials compensated for the rest. Further research can improve the Environmental Product Declaration (EPD) of materials and assess the entire building life cycle.

The contribution focuses on the design project in particular in relation to the existing Cultural Heritage. The principle aim is the investigation and the analysis of a complex as an indispensable relationship between the phase of building knowledge and that of intervention. Methodologically this question will be addressed firstly through a historical excursus through the main restoration theories with the aim of understanding how this aspect has always been perceived as a fundamental element for the success of the project; then it will be addressed towards the study and investigation of some more recent methodological solutions. Outcome, still open to development and progress scenarios, is the evaluation of how the most recent technologies and information systems can be able, if wisely used, to became tools able to assist the designer in the synthetic control of the management of the building process.

The theme of urban regeneration is currently one of the main actions of transformation policies. It presents an opportunity for cities’ design, in particular historical centers, through joint actions aimed at creating synergies and connections between social, political, economic, and environmental aspects. It also becomes an opportunity to enhance the huge and complex Cultural Heritage, full of architectural values, memory, and history. At the same time, it appears increasingly inadequate and obsolete compared to the new needs of a changing society, of regulatory aspects, and of a general compatible approach to intervention to the more general policies of sustainable development, as required by the 2030 Agenda for Sustainable Development. A total of two case studies of the reuse and enhancement of hospital buildings of the University of Pavia are presented, which has a large building heritage spread throughout the city. In recent years, owing to the opportunities offered by funding, it has started transformation policies on some abandoned buildings through projects based on an interdisciplinary approach and a participatory design strategy. The article testifies to a potential method of intervention that can be exported to other contexts, after a previous test of the compatibility on the existing and on the urban context.

This study presents an integrated intervention strategy for the adaptive reuse of vernacular architecture in a state of ruin, focusing on the fortified village of Moya (Cuenca, Spain). The proposal is framed within a rural revitalization program aimed at educational and cultural tourism uses, with the goal of reactivating abandoned built fabric through the incorporation of new functions that generate social value and contribute to territorial development. The proposed methodology combines archival research, digital documentation, material characterization, and a constructive solution based on the insertion of a reversible, structurally autonomous timber volume within the existing stone masonry. Through material characterization, a differentiated consolidation protocol is developed to stabilize the ruins while maintaining historical legibility. The new architectural volume, built with prefabricated cross-laminated timber (CLT) and insulated with locally sourced expanded cork, is designed to meet contemporary standards of energy efficiency, reversibility, and environmental responsibility, while remaining fully independent from the original structure. The intervention offers a replicable model for sustainable rural regeneration, balancing conservation ethics with functional adaptation. Future lines of research include the dynamic simulation of the energy performance of the inserted dwelling, with the aim of assessing its contribution to climate neutrality and net-zero emissions targets.