In many cultures, fire is a sacred element used in rituals of rebirth and renewal. It carries a dual symbolism, being both a creator and a destroyer—capable of illuminating paths or consuming everything in its wake. In Greek mythology, for example, Prometheus stole fire from the gods and gave it to humanity, marking it as a symbol of progress, knowledge, and creative power. However, fire also evokes destruction, as seen in biblical tales like that of Sodom and Gomorrah, where it was used as divine punishment. This duality was also evident in the 2019 fire at Notre-Dame Cathedral, which devastated its historic structure. The disaster sparked a wave of solidarity and led to unprecedented technological advancements, with restoration efforts utilizing digital tools such as laser scanning and Building Information Modeling (BIM) to recreate intricate details and preserve architectural heritage.
Even before firefighters fully extinguished the flames, a surge of donations flowed in for this symbol of Western civilization built in the 12th century. Among the restoration efforts, Autodesk played a pivotal role by contributing technology and expertise, providing its software, and creating detailed BIM models of the cathedral for reconstruction. These digital tools enabled precise planning and collaboration, ensuring that intricate structural details and historical authenticity were preserved while demonstrating how technology can be a powerful ally in efforts to conserve built heritage. We spoke with Nicolas Mangon, VP of AEC Industry Strategy at Autodesk, about this process and how BIM usage benefited the cathedral's reopening.
The 3D BIM model was created through a combination of laser scanning, photogrammetry, and drone footage, taking over a year to complete. This effort resulted in a detailed digital twin of the structure as it appeared before the fire. The project was a collaboration between Autodesk and Art Graphique & Patrimoine (AGP), a leading French company specializing in laser scanning and digitizing historic monuments. The model was essential in addressing three major challenges: facilitating collaboration among more than 200 companies and 2,000 individuals involved in the project, meeting the ambitious five-year restoration timeline, and overcoming the limited documentation of the cathedral's original design. The BIM model also enabled precise planning, construction phase simulation, and early identification of potential issues, ensuring the project stayed on track.
We collected billions of points to capture every intricate detail of the cathedral, from its vaulted ceilings to its iconic spire. Because of the complex structural details and sheer size of the Notre-Dame, it took over a year to create the full-scale model as it existed before the fire. No one had built a spire like this in over 100 years, and the 3D model was used to guide the new design to honor its historic integrity as well as test and understand its stability against storms. – Nicolas Mangon
The model guided the project to honor its historical authenticity while incorporating modern engineering to enhance resilience against environmental stressors such as storms. Additionally, the mapping facilitated logistical planning, particularly given the site's limited storage and restricted access. By simulating material deliveries, worker routes, and construction phases, it improved efficiency and safety throughout the process.
The 3D BIM model was the solution to these challenges; it enhanced collaboration, clarity, and efficiency across the reconstruction teams, was used to simulate and plan every phase of construction, and predicted issues that could arise before they occurred on the jobsite. The BIM model, and our software, which Autodesk donated to the Établissement public Rebâtir Notre-Dame de Paris, provided a shared and scalable 3D database to guide collaboration amongst the project's architects, engineers, and historians. – Nicolas Mangon
The shared BIM platform served as a central database, enabling architects, engineers, historians, and restoration specialists to work cohesively. This unified approach ensured that every restoration phase adhered to historical integrity and modern safety standards. The restoration of Notre-Dame has also set a benchmark for the use of BIM technology in preserving other cultural heritage sites. As Mangon points out, this project shows the importance of proactive measures, such as the digital documentation of historic landmarks, to safeguard them against potential disasters. Beyond restoration, BIM's predictive capabilities can simulate how structures will respond to environmental challenges, guiding maintenance and conservation strategies for future centuries.
The restoration of Notre-Dame transcends a mere recovery effort—it stands as a pivotal moment in marrying technology with historical preservation. Leveraging 3D BIM modeling allowed for unparalleled precision and efficiency, raising the bar for safeguarding historic monuments. By uniting specialists across disciplines on a single collaborative platform, the project exemplified how technological innovation can secure cultural heritage for future generations. This achievement underscores the critical need to invest in the digital documentation of global landmarks—a forward-looking approach that strengthens resilience against the dual tests of time and environmental adversity.
