The digital transition is one of the biggest challenges of the new millennium. One of the key drivers of this transition is the need to adapt to the rapidly changing and heterogeneous technological landscape that is continuously evolving. Digital Twin (DT) technology can promote this transition at an urban scale due to its ability to monitor, control, and predict the behaviour of complex systems and processes. As several scientific studies have shown, DTs can be developed for infrastructure and city management, facing the challenges of global changes. DTs are based on sensor-distributed networks and can support urban management and propose intervention strategies based on future forecasts. In the present work, a three-axial operative framework is proposed for developing a DT urban management system using the city of Venice as a case study. The three axes were chosen based on sustainable urban development: energy, mobility, and resiliency. Venice is a fragile city due to its cultural heritage, which needs specific protection strategies. The methodology proposed starts from the analysis of the state-of-the-arts of DT technologies and the definition of key features. Three different axes are proposed, aggregating the key features in a list of fields of intervention for each axis. The Venice open-source database is then analysed to consider the data already available for the city. Finally, a list of DT services for urban management is proposed for each axis. The results show a need to improve the city management system by adopting DT.

Cities are complex and constantly evolving systems where changing social needs have always reshaped the built environment. Considering recent evolutionary trends in housing emergencies, amplified by the COVID-19 pandemic, and environmental sustainability goals, a rethinking of the building heritage is fundamental. This article aims to promote the conversion of buildings designed initially for nonresidential uses as a process and project strategy based on energy efficiency and a holistic and integrated vision of the circular economy. The methodological approach is based on two main phases: definition of evaluative parameters for the potential reuse of a building, and integration of the evaluation system in a BIM and GIS environment. The result is a tool for rapid automatic pre-evaluation of the potential conversion of a building into a residential space. Applying the developed methodology allows for a practical approach to the significant issue of sustainable construction, with particular attention to energy improvement and the reduction of environmental impact related to the construction of new buildings. The originality of the contribution lies in the systematization of various digital technologies to provide fundamental support for managing and transforming the varied and widespread unused real estate assets in a state of abandonment and degradation.

The reprocessing, preservation, and maintenance of the wide historical architectural heritage in Italy represent one of the main challenges of digitalization; not only it is one of the oldest among in Europe, but it is also widespread across the country between cities and rural areas. The care of such an aging built environment needs a carefully planned approach that can take advantage of new technologies such as Historical/Heritage Building Information Modelling (H-BIM) and Digital Twin (DT). The final goal is to promote a long-term sustainable restoration with high qualitative standards. Usually, the topic of sustainability is discussed for new constructions where it is of fundamental importance to save materials, energy, land use and to reduce the carbon footprint. However, being the number of historical buildings elevate in Italy, the concept shall be extended also to them, that are way more fragile if compared to the surrounding. Moreover, cultural heritage is connected to specific challenges that need to be addressed. What was happened in Aquila region after the earthquake of 2019 must not happen again. Digital technologies can be used to prevent such a catastrophic event, preventing and limiting damages, providing evaluable information, and realizing a tool that can be shared among the stakeholders to restore the physical and cultural value of an historical building also in case of extreme events.

Since 2010 United Nations declared that for the first time in history up to 50% of mankind is living in urban areas, implying that challenges connected with global changes need to be evaluated primarily within urban systems, using the most advanced available technologies. Earth observation is nowadays the most promising field of research assisting urban planners, city managers, and building designers in their work of improving urban resilience to cope with climate change effects, and the long-term changes connected with extreme climatic events. Even though the deep understanding of the functioning of urban systems is a key factor for improving the quality of life at all levels, urban development is still poorly monitored globally, and reliable and comparable satellite urban data across countries is still limited, slowing down international comparative research. The Copernicus UE programme, replacing the Global Monitoring for Environment and Security (GMES) programme, recognizes the strategic importance of Earth observation for emergency management. Copernicus programme provides global, continuous, autonomous, high quality, wide-area Earth and Atmosphere observation. Copernicus links Space observations to ground-based and atmospheric data collection and processing, providing operational services in the fields of environment, ground infrastructures, civil protection, and security, supporting the implementation of a large number of sectorial and transversal public policies. Of the six thematic macro-areas of the present programme observation and ground monitoring of the European urban systems lies in the first thematic area of the land monitoring service. The enormous and continuous data generation from the Copernicus programme is allowing the construction of an accurate and up-to-date database to the state of health of our cities and surrounding environments, providing research materials simply inconceivable only a few decades ago.

Historical building reuse is aimed at preservation, where buildings are recovered for new uses connected to cultural activities. This paper presents the analysis of the impact of thermo-fluid dynamics due to a 500 kW electrical power transformer installed inside a historical building. The analysis is performed using computational fluid dynamics simulations validated through measurement campaigns carried out during the summer period. High temperatures and wide humidity variations can damage building plasters and cause malfunctions in power equipment. To avoid these situations, two different installation layouts were studied. One consists of the power transformer directly installed in the environment and cooled by an inlet fan, and the other consists of the power transformer being insulated from the external environment by an enclosure connected to a forced ventilation system. The second layout showed better results both inside and outside the transformer enclosure. The maximum indoor condition was about 4.3 °C, with a −7.2% RH and an airflow rate of 1100 m³/h, and the maximum outdoor air condition was 3.3 °C, with a −1.39% RH and a flow rate of 2200 m³/h. However, the temperatures and humidity inside the building and outside the transformer enclosure were almost the same.