As European cities increasingly explore digital twins to support urban planning and decision-making, the need for open, interoperable, and scalable solutions continues to grow. The newly launched EU Local Digital Twin (LDT) Toolbox aims to help municipalities accelerate their digital twin journey while reducing vendor lock-in and fostering collaboration across Europe. For the European Citiverses Uniting for Inclusiveness project, initiatives such as the LDT Toolbox are particularly relevant. They provide an important foundation for creating digital twins that are not only technically advanced, but also inclusive and responsive to the diverse needs of citizens.
We asked Claus Popp Larsen, Focus Area Leader for Connected Cities at RISE, to share his key takeaways from the launch event in Valencia.
1. Claus, you participated in the EU LDT Toolbox: Launch Event – Interoperable Europe Portal. What was the purpose of the event?
The purpose of the event was to officially launch the LDT Toolbox. LDT means local digital twin, which is EU terminology for a digital twin or a replica of a municipality’s physical environment and assets. The EU has invested more than €100 million over several years into this initiative, and the time had come to showcase it to the world, celebrate its release, and discuss the next steps. It was a brilliantly orchestrated two-day event in Valencia, hosted by the Spanish company Nunsys, which led key parts of the toolbox's development. (Note: RISE contributed to the final stages of development by validating code and licensing conditions).
2. What are the key insights regarding the LDT Toolbox’s potential and future that you’re taking away from the event?
The LDT Toolbox is a collection of shared, open-source, and interoperable components designed to make it much easier for municipalities to develop their own digital twins—all while minimizing the risk of vendor lock-in.
I personally love the concept of community-driven development for digital twins. It allows one municipality to easily replicate what another has already built, creating an ecosystem where everyone can contribute to improving existing tools or developing new ones. Some of these tools have already been trialed by pioneering cities who shared their experiences at the launch. For instance, we saw examples of simulations for flooding and heat waves, which help cities understand their vulnerabilities and build greater resilience.
While the potential of the toolbox is nearly limitless, we also need a quick reality check:
· It is ready for use, but it is not perfect or complete. That is entirely normal for a fresh launch, but it will still require significant development to reach its full potential.
· There is currently no sustainable governance model. Critical questions regarding who will maintain the code, how new tools will be integrated, and what the underlying business models look like remain unanswered. Fortunately, both the EU Commission and the LDT Citiverse EDIC (which will eventually oversee the toolbox) are well aware of this and are actively discussing solutions.
So, to put it simply: the LDT toolbox is a precious diamond, but it is still rough and uncut!
3. Based on what was presented at the event, how ready are European cities to work with the LDT Toolbox?
The cities presenting their use cases at the event noted that it was relatively easy to get started and combine different tools in various ways. Because of this, I believe anyone with the right technical skills can jump right in and start working with it.
However, much like any digital twin framework, the LDT Toolbox is highly data-hungry. Generally speaking, municipalities still have a long way to go before they can manage, curate, and share their data effectively enough to fully unlock the potential of digital twins. This is by no means a flaw in the LDT Toolbox itself. On the contrary, adopting and exploring the toolbox may serve as the exact catalyst municipalities need to upgrade their data capabilities.
