France: What Restoration for Notre-Dame de Paris?

Having graduated in 2020 from the Ecole de Chaillot, which trains heritage architects, specializing in architectural, urban, and landscape conservation and restoration, Fr. Desjobert is participating in the study of the cathedral’s restoration.

Starting by recalling that in France, restoration has been the subject of a real science for nearly 200 years, the young Dominican emphasized that the proposals for a contemporary spire - launched a few days or a few weeks after the fire - received no support from the public nor from the architects “because they had not taken the time for in-depth work.” Indeed, he adds, “a restoration requires more than a few hours of work and a publicity stunt.”

“For Notre-Dame, it is a question of understanding what are the 'pathologies' that the building has known for 800 years. She is an old lady on whom we must intervene without further weakening her,” continues the Dominican.

The first step was to safeguard the building. One of the guiding principles of Gothic religious architecture is the notion of verticality. The elevation of the building is in the image of the elevation of the soul to God.

The invention of the flying buttress enables it to perform the functions of buttressing the central vessel and its vault. The flying buttresses compensate for the weight of the vault and the roof.

However, since the fire, without a roof and with a damaged vault, the cathedral has been at risk of collapse. Therefore, as a priority, it was necessary to support all the flying buttresses with wooden arches.

If in the eleventh century they had begun to erect vaults over the nave of churches, it was already to protect them, especially from fires, explains the Dominican.

It was in the 1830s that the notion of patrimony and the question of its restoration emerged. The cathedral was then in rather poor condition. Many elements had degraded, as with many of the 40,000 religious buildings that the Revolution had decommissioned.

Under the Ancien Régime, the durability of religious places was linked to their use. We must therefore find the means to ensure the conservation of this endangered heritage.

Currently, faced with the abandonment of the maintenance of churches and convents, the restorers are following the Venice Charter of 1964. It stipulates, among other things, that the restoration is to be based on respect for the old substance and authentic documents. It stops where the hypothesis begins.

It is always accompanied by an archaeological and historical study of the monument. “One can find there arguments both for and against the idea of ​​an identical repair or the possibility of contemporary additions,” comments Fr. Desjobert.

Notre-Dame de Paris was originally built on the site of earlier buildings. It was placed next to the old Carolingian cathedral so that it could still be used during construction.

The construction began with the choir to go to the facade. The choir was erected fairly quickly, from 1163 to 1182. It was then closed by a wall and they began to celebrate Mass there. During construction, the number of levels of elevation was reduced from four to three, under the influence of contemporary constructions, such as Saint-Denis, Sens, or Chartres.

The spire was built between 1220 and 1230, when the two parts of the building, the nave and the choir, were connected. This spire weakened over time and part of it collapsed in 1606. It was finally dismantled at the end of the 18th century, explains the Dominican.

The architect Eugène Viollet-le-Duc was commissioned in 1844, at the age of thirty, to restore Notre-Dame de Paris. He would devote twenty years of his life to it.

For Viollet-le-Duc, restoring a building is restoring it to a complete state which may never have existed. He wanted be in accordance with the ideal that its original designers had. This was based on a thorough analysis of the buildings. Included among his works, were the repair of the frames of the two arms of the transept, the spire, and the spans of the central vessel bordering the spire.

In the context of the current restoration, the vision of the heritage architects for an identical reconstruction has come to prevail. Fr. Desjobert takes up the arguments of Benjamin Mouton, former chief architect of historical monuments:

- The invisible has value too. A restoration, especially for a Gothic building, cannot play on  “duplicity” which would respect the external appearance, but whose structure would be different.

- Furthermore, fire does not prohibit the use of wood; Notre-Dame’s frame had survived 800 years during a period when open flames were used much more as a source of light or heat.

- A heavy roof is required to verticalize the static loads. Oak and lead by their density meet this requirement. The framework is fully documented. In fact, the architects have millimeter readings of the frame made in 2015 and a digital survey of the frame made in 2014. It can be reconstructed while remaining perfectly faithful.

Shortly after the fire, Frédéric Epaud, archaeologist, researcher at CNRS, and specialist in wood and medieval frames, explained that the wood used in medieval frames was cut green and put in place shortly after the trees were felled.

He specified that the construction of the Gothic framework of the nave, the choir and the transept of Notre-Dame had used around 1000 oaks, the majority of which were young, with an average age of 60 years.

“The forest areas used by these large projects represented only a few hectares, far from the legendary clearing of entire forests for the construction of Gothic cathedrals.”