In a context where digital giants are increasingly influencing the actions decided by public policies, smart data platforms are a tool for collecting a great deal of information on the territory and a means of producing effective public policies to meet contemporary challenges, improve the quality of the city, and create new services. Within the framework of the Smarter Together project, the cities of Lyon (France), Munich (Germany), and Vienna (Austria) have integrated this tool into their city’s metabolism and use it at different scales. Nevertheless, the principle remains the same: the collection (or even dissemination) of internal and external data to the administration will enable the communities, companies, not-for-profit organizations, and civic administrations to “measure” the city and identify areas for improvement in the territory. Furthermore, through open data logics, public authorities can encourage external partners to become actors in territorial action by using findings from the data to produce services that will contribute to the development of the territory and increase the quality of the city and its infrastructure. Nevertheless, based on data that is relatively complex to extract and process, public data platforms raise many legal, technical, economic, and social issues. The cities either avoided collecting personal data or when dealing with sensitive data, use anonymized aggregated data. Cocreation activities with municipal, commercial, civil society stakeholders, and citizens adopted the strategies and tools of the intelligent data platforms to develop new urban mobility and government informational services for both citizens and public authorities. The data platforms are evolving for transparent alignment with 2030 climate-neutrality objectives while municipalities strive for greater agility to respond to disruptive events like the COVID-19 pandemic.

The Smarter Together project implemented in the three lighthouse cities (LHCs) of Lyon, Munich, and Vienna a set of co-created and integrated smart solutions for a better life in urban districts. The implemented solutions have been monitored using a novel integrated monitoring methodology (IMM) following a co-creation process involving key stakeholders of the LHCs. With focus on holistic building refurbishment and the integration of onsite renewable energy supply (RES), the three LHCs refurbished around 117,497 m2 of floor area and constructed 12,446 m2 of new floor area. They implemented around 833 kWp of PV, 35 kW of solar thermal and 13,122 kW of geothermal heating systems. Altogether, the realized solutions for low-energy districts in the three LHCs will annually save around 4000 MWh/a, generate 1145 MWh/a of RES and reduce around 1496 tCO2/a of CO2 emissions, corresponding to specific values of 37.6 kWh/m2.a and 11.9 kg-CO2/m2.a for final energy saving and CO2 emission reductions, respectively. KPI-based monitoring and evaluation of the implemented solutions provides qualitative and quantitative insight, experience and lessons learned to optimize the process of implementation and deployment of integrated solutions for holistic building refurbishment, and thus contribute to advancing sustainable urban transformation at the district level for both LHCs and FCs.