3D rendering has played a key role in the restoration of Notre-Dame cathedral in just five years – something that would have been almost impossible using only traditional methods. Roderick Bates of Chaos looks at how the technology shape the planning, design and building of the reconstruction, and how it can futureproof historic buildings
On 15 April 2019, tragedy struck Paris when a devastating fire broke out in the Notre-Dame Cathedral, likely caused by an electrical fault or a burning cigarette. The flames consumed the cathedral’s roof and spire, destroying key components of the 850-year-old Gothic masterpiece, shocking both the city and the world.
Five years and over €700m later, the treasured building is restored, fulfilling an ambitious promise made by President Macron to reopen the building before 2025.
If the restoration were limited to traditional methods, the immense project would never have been completed on such a tight schedule. Instead, the successful completion was possible through the extensive use of 3D rendering technology to precisely design, plan and build the reconstruction.
The importance of documenting architectural details
The architectural intricacies of Notre-Dame would be almost impossible to replicate without an initial scan or model to reference.
Fortunately, art historian Andrew Tallon captured scans of the cathedral’s original greatness just four years before the fire for an alternate project, creating a detailed 3D map of the structure.
This created a crucial reference for the detailed features throughout the cathedral, capturing the nuances missing from the historical drawings, such as flying buttresses, stained glass windows and precise carvings. Without these scans, the final restoration would have necessitated significant guesswork at the “authentic” design details.
However, while they proved a critical data point, they fell short of providing the highly detailed modelling necessary for an entirely faithful restoration.
Fortunately, modern 3D rendering technology filled the gap, providing the key visual component required to revive the iconic structure.
The acceleration of historic restoration through 3D rendering
Detailed 3D renders enable restoration teams to overlay historic maps with current post-damage images, creating a visually realistic composite to quickly assess the extent of the destruction and the structural integrity.
Planners used this information to accurately estimate the labour and materials needed, maximising the efficiency of recovery efforts while controlling costs.
Furthermore, the 3D model will serve as a valuable asset for ongoing maintenance to ensure the preservation of the restoration. The restoration team – architects, engineers, construction workers and conservationists alike – can work collaboratively using the rendered images.
As renders, they present as visually realistic digital environments, providing a crucial shared artefact for communication that is easily understood and navigated. This approach ensures that the process runs smoothly, allowing each team to understand the impact of their contributions on the overall project.
Additionally, when dealing with national treasures like Notre-Dame, public opinion is crucial to designers, as the public holds a majority stake. To engage stakeholders, the Parisian public were presented with four accessible 3D renders, allowing them to vote on their preferred design.
Therefore, a balance between expertise and public sentiment was struck throughout the entire restoration process.
While 3D rendering was clearly key to the restoration of Notre-Dame, its broader potential lies in safeguarding future historic preservation projects.
Futureproofing and the mitigation of risk
Futureproofing buildings starts with addressing safety risks during the design phase. With 3D rendering, construction teams gain precise visualisations of the building, enabling safety staff to strategically optimise the placement of essential safety features.
However, approximately 5,475 fires take place in Europe daily, highlighting that while avoidance of fire hazards is a safety priority, it will continue to be a significant threat to new and historic buildings.
The risk of fire and the resulting tragic destruction of cultural landmarks makes it incredibly important to have a digital record to guide restorations. Even if a post-disaster restoration isn’t feasible, a complete digital record will allow the building to live on and be experienced by others, if only virtually.
Proactive futureproofing and collaborative restoration
The Notre-Dame restoration serves as an inspiring example of cultural revival and a lesson in the importance of proactive detailed data collection when preserving historic buildings.
Combining the pre-fire digital maps of Notre-Dame with rendering technology during design made possible the restoration of this iconic landmark in only five years – a timeline once thought impossible.
Preserving historic landmarks such as this requires input from diverse stakeholders, reflecting the cultural significance of historic buildings. At Chaos, we are dedicated to making the design process accessible, empowering everyone to contribute to projects of this significance.
