Digital Twins to Transform Brownfields into Neighborhoods

In Luxembourg, Agora is leveraging the integration of BIM and GIS to transform the former industrial brownfields of Belval and Metzeschmelz into vibrant and sustainable urban districts. This innovation was recognized this summer with a SAG Award.

Founded 25 years ago in Luxembourg, Agora is a highly atypical organization. Jointly owned by the Luxembourg State and ArcelorMittal, its mission is to redevelop former steel industry brownfields into modern urban neighborhoods. “We are therefore not a traditional urban planning agency, but a developer specialized in industrial brownfields,” explains Alexandre Londot, Chief Operating Officer at Agora. “We support developers and investors up to the building permit stage, and we are also considering taking on a role as builder ourselves, for example by constructing affordable housing units and mobility hubs.”

Agora’s first major development site was Belval, covering 120 hectares. A former steelmaking site, it has now become a flagship district of the city of Esch-sur-Alzette and the municipality of Sanem. Since 2017, the company has also been leading the development of Metzeschmelz, a second brownfield of 62 hectares spanning Schifflange and Esch-sur-Alzette. “These are exceptional projects,” notes Alexandre Londot. “They involve decontamination, dismantling of infrastructures, but also the preservation and rehabilitation of certain buildings in order to safeguard our industrial heritage.”

With a team of around twenty employees, Agora works with numerous external firms (architects, urban planners, engineers) and has made GIS a central collaborative working tool: “It is undeniably the foundation of our digital strategy, both a technical tool and a communication facilitator around which everyone works,” says Dominique Seelen. He joined the development company eight years ago and is now a GIS Analyst. Trained as a geographer and having entered GIS support, he acts as a bridge between IT and geography. His role has been to progressively structure the GIS architecture around ArcGIS Pro and ArcGIS Online. “At first, we were still working in 2D with ArcMap to produce simple PDF maps. The shift to ArcGIS Pro enabled us to move to 3D and share our maps online across the whole organization,” he explains.

All employees now have an ArcGIS Online account in viewer mode, allowing them to explore maps and overlay different layers of information. “This makes decision-making easier without requiring me to intervene for every map change,” notes the GIS specialist. Partnering architecture and engineering firms also have external access to the maps, ensuring a smooth collaboration. Today, Agora uses a wide range of Esri platform extensions: 3D Analyst, Spatial Analyst, Data Interoperability. “We were also the first in Luxembourg to use ArcGIS Urban,” adds Dominique Seelen. “And that changes a lot when it comes to automating urban calculations.” Esri Belux played a key role in the implementation of the various GIS components, supporting Agora with technology monitoring and training. “Without this support, we would not have been able to move forward so quickly, stay at the forefront, and evolve our practices,” acknowledges Alexandre Londot.

To go beyond mapping, Agora chose to cross GIS data with BIM models, even though Alexandre Londot recognizes that “it is not always easy to trace the boundary between the two worlds. The key is to make them communicate.” He set up a process to manage data interoperability: “IFC models from Revit are first integrated into ArcGIS Pro via the BIM to Geodatabase tool. They are then converted into Scene Layer Packages to be published in ArcGIS Online. I developed a Python script that automates this workflow, removes unnecessary elements such as Opening Elements—3D objects generated in IFC that are not recognized by ArcGIS—and manages the transformation of coordinate systems, since Luxembourg has its own reference system: LUREF.” This automation, which could inspire many others, has made the BIM-to-GIS process more reliable and faster. “Importing an IFC takes around 30 minutes, but now I can process several models in parallel. This is what enabled us to build coherent and usable Digital Twins,” he says proudly.

In Belval, the Digital Twin was initially used to reconstruct the existing environment. “We reintroduced the plans of the already built structures and reintegrated all networks and infrastructures,” explains the GIS specialist. “Gradually, we required architects to use digital models from the competition stage onward, so that their projects could be directly incorporated into our model. Today, ArcGIS Urban enables us to go further: we can automatically calculate surfaces, the number of housing units and inhabitants, or estimate the needs for services and commerce. Each lot can be analyzed individually according to different metrics via an interactive dashboard.” 
“This Digital Twin now serves as a management tool,” adds Alexandre Londot. “It enables us to continuously measure urban density, anticipate public service needs, and compare in real time different variants of the Plan d’Aménagement Particulier (equivalent to a local zoning plan). It has become an essential tool for consultation and negotiation with municipalities, developers, and investors.”

In Metzeschmelz, the approach was different. In this case, everything began with the complete digitization of existing buildings, including basements and technical galleries. “It is a former factory with complex underground structures. We modeled everything to ensure a reliable base,” says Dominique Seelen. The project is still in the preliminary landscape design study phase, but all data is already integrated into the GIS. “Here, the Digital Twin is primarily a tool for anticipation,” explains Alexandre Londot. “It helps us assess constraints inherited from the industrial past, identify sensitive points, and test different redevelopment scenarios before finalizing a master plan.” Unlike Belval, the objective here is less immediate densification and more building a realistic and secure framework for future transformation.

These Digital Twins are not limited to technicians. “At first, they were working tools. But we soon used them for communication purposes as well, to demonstrate the attractiveness of the district to decision-makers and institutional stakeholders.” The experience at the international MIPIM fair in Cannes since 2023 illustrates this. An interactive 3D model presented on 4K touchscreens drew strong attention. “More than a gadget, it showcased the coherence of the urban project to a wide variety of partners, from policymakers to the general public,” emphasizes the Chief Operating Officer. In the long term, Agora even plans to transfer the Digital Twins to municipalities to replace paper as-built plans. “This will facilitate infrastructure management and maintenance.”

Although Agora’s Digital Twins are already operational, the story is just beginning. The team plans to integrate new technological components: energy, hydraulic, or climate simulation; real-time traffic data; and possibly IoT and connected sensors. “We are also considering augmented reality to visualize building basements or networks onsite through a tablet. That would be a natural evolution,” imagines the GIS manager.

Agora’s innovative approach was recognized by the global Esri user community. During the 2025 annual conference, Agora received a prestigious SAG Award. “It is a meaningful acknowledgment of our work and of the contribution of GIS and BIM in shaping the city,” says Alexandre Londot. With its two flagship projects, Agora has demonstrated that a Digital Twin is not merely a 3D visualization, but a true planning, management, and collaboration tool. By leveraging ArcGIS and a carefully designed integration between BIM and GIS, the Luxembourg developer has positioned itself as a European pioneer, transforming the redevelopment of industrial brownfields into a showcase of sustainable urban innovation.