As cities face growing pressure to manage digital transformation responsibly, there is a need for practical solutions that support ethical, transparent and inclusive approaches. The Eurocities Digital Forum Lab (available to Eurocities members only) is set up to meet this need, helping cities build capacity and share knowledge on digital governance.
Its work in 2025 focused on three key areas: Ethics and Innovation, Digital Twins, and Public Sensors. Through these workstreams, the Lab offers cities concrete tools and strategies to embed public values in their digital policies and ensure technology serves people and places.
“Through the Digital Lab, we’re creating a space for our members to work collaboratively and turn abstract principles into concrete action, so that their digital services deliver for people in a trusted environment,” says Chiara Venturini, Head of Digital Transformation at Eurocities.
Helping cities unlock the potential of digital twins
Cities are increasingly adopting digital twins as important tools for different aspects of urban planning. By creating real-time, data-based models of urban systems, digital twins can support decision-making, test scenarios and improve service delivery. Through collaborative learning and experimentation, the Digital Forum Lab identified key insights to help European cities run successful digital twin initiatives.
One of the most important lessons is the need for a clearly defined purpose. Cities found that starting with specific, real-world problems (such as climate resilience, mobility management, or urban planning) helps avoid creating digital twins without meaningful use. This focus ensures the technology addresses genuine city priorities.
Governance, trust and transparency
Governance also emerged as a critical factor. Successful projects involve diverse stakeholders from the outset, including policymakers, technical experts, civil society, and local communities. Strong leadership and coordinated efforts help align digital twin development with broader city strategies and prevent fragmented or duplicated efforts. Cities are also setting up dedicated steering committees to ensure clear roles, data ownership and coordination across departments.
Building a digital twin is not only a technical challenge – it also raises questions about governance, skills and data. Cities need to consider not only compliance with legal requirements, but also the integration of ethical guidelines into design and implementation. This means involving citizens and stakeholders early, ensuring transparency, and promoting trust.
Building trust is essential: digital twins are still relatively new technologies, and without clear communication and engagement, they risk being misunderstood or resisted. Providing accessible information, aligning with public values, and explaining how decisions are made with digital twins are key to ensuring these tools serve the public good. Cities also emphasise designing digital twins for long-term sustainability, both environmentally and financially, ensuring the tools can evolve with changing urban needs.
Capacity building is another shared learning. Digital twins require multidisciplinary skills that many cities are still developing. Investing in staff training, fostering cross-sector teams, and leveraging existing platforms have proven effective strategies. Collaboration with universities and peer cities further supports knowledge exchange.
Data and technical foundations
Access to high-quality, interoperable data proves essential, yet cities often grapple with siloed datasets, privacy concerns, and licensing challenges. Many are tackling this by establishing clear data governance frameworks and forging partnerships with local and national data providers. Adopting open standards, modular architectures and federated systems also ensures flexibility, avoids vendor lock-in, and makes cross-city collaboration easier.
From a technical perspective, cities emphasised the value of open, flexible, and scalable solutions that can evolve over time. Ensuring interoperability between systems is key to maximising the long-term benefits of digital twins. Cybersecurity and compliance with regulations like GDPR and the EU AI Act are also key considerations, particularly as data flows become more complex.
Finally, measuring and demonstrating value is vital for sustaining support. Cities are developing indicators tied to their original goals and sharing both successes and setbacks openly to build trust and encourage ongoing investment.
Supporting cities with developing their digital twin
These insights are captured in the Guidelines for developing digital twins (accessible to Eurocities members only), a practical resource that summarises the collective experience of the Eurocities Digital Forum Lab. The guidelines provide a roadmap for cities ready to move from experimentation to impactful deployment.
“The goal of these guidelines is to cover as many perspectives as possible without going into too much detail, targeting people who are not familiar with digital twins but need to have a broad idea about the impact of deploying digital twins in their city,” explains Jordi Ortuño, Innovation Manager at the Knowledge Society Office of the Barcelona City Council, who lead the work of the Lab on Digital Twins. “We have included other dimensions, like training and education, the citizen perspective, because we are not only considering the technological aspects.”
Examples from the ground
Examples from across the Eurocities network show how cities are approaching these challenges in practice.
Rotterdam, for instance, is focusing on climate resilience by building a dynamic digital twin that models the effects of climate change on urban infrastructure. By combining meteorological data, hydrological models, and infrastructure information, the city can simulate flood scenarios and evaluate mitigation measures before physical implementation.
Dublin is advancing a mobility-focused digital twin that integrates data from traffic sensors, public transport systems, and pedestrian flows. This allows the city to test interventions such as changes to traffic light timing or the introduction of dedicated bus lanes, reducing congestion and improving travel times.
Rennes Metropole is using its digital twin for urban planning and public engagement. Planners can simulate the impact of new real estate developments on shading, ventilation, and energy efficiency, while interactive 3D visualisations allow residents to better understand future urban projects and participate in consultations.
Milan is exploring a digital twin to monitor and improve air quality and green spaces. By linking environmental sensor data with predictive models, the city can assess the effectiveness of different green infrastructure strategies, such as adding green roofs or expanding tree coverage, to combat urban heat islands and pollution.
SmartLamppost, a collaborative initiative in several Portuguese cities, demonstrates the value of shared digital infrastructure. Equipped with sensors, connectivity, and data-sharing capabilities, these smart lampposts support multiple applications, from environmental monitoring to public lighting management, while acting as a backbone for broader digital twin solutions.
What’s next?
The Guidelines for developing digital twins were co-created by the cities of Barcelona, Brussels, Cologne, Eindhoven, Lisbon, Madrid, Munich, Nicosia, Oulu, Riga and Utrecht, as part of the 2025 Eurocities Digital Forum Lab. They are the first in a three-part series of outputs from this year’s Lab, followed by ethical digital innovation and the role of public sensors in smart urban transformation.
The call for pitches for the 2025–2026 Digital Forum Lab is now open. Cities interested in presenting their digital transformation solutions as best practices and collaborating with other cities can submit their proposals by Wednesday, 10 September 2025, close of business.
Additional information about the Lab, its objectives, and outcomes from previous iterations is available on the Eurocities Collaboration Space.
