Research, Technology & engineering

Just what will the rebuilt Notre Dame look like?

By John Hickey

Notre Dame de Paris

How to replace the spire that had soared above Notre Dame de Paris before the April 15 fire will be at the heart of renovation discussions. (Photo by David Monniaux via Wiki Commons)

Less than two weeks have passed since fire hit Notre Dame de Paris, incinerating the distinctive gothic spire and destroying the cathedral’s roof while leaving char and smoke damage along the walls.

Nearly a billion dollars has poured in to help rebuild the famed cathedral.

And even as plans have not yet solidified around exactly what the rebuild should look like, there is already great interest and speculation.

The early hope among donors is that when the work is completed, the cathedral will look very much like it looked on April 14, the day before the fire struck.

Henrike Lange, assistant professor in UC Berkeley’s departments of History of Art and Italian Studies, says the spire that came crashing down on live TV is likely to return looking much like it did before if those donors have their way.

“People want to just restore what they have seen before,” Lange says. “I think you’ll see that the (major) donors are from that age group.”

Yet, she points out that the make-it-just-like-before consensus may not survive the realities of rebuilding.

“Like so many cathedrals, Notre Dame has been in a process of continuous building and rebuilding over many centuries,” she says.

And what history shows is that each rebuild leaves the Roman Catholic Church’s focal point in Paris looking different.

An expert of medieval and early modern European art and architecture, Lange lived in Paris before moving to the United States, conducting research on Gothic materials at the Ecole du Louvre and working for binational collaborations at French and German museums and universities.

Lange and two other specialists from Berkeley, Patricia Yu and Matthew DeJong, warn that those wanting to see Notre Dame emerge just like it has since the mid-19th century may well be in for a disappointment.

DeJong, a Berkeley assistant professor in structural engineering, did a Q-and-A for the university’s engineering website about what is next for Notre Dame.

The very fact of saving Notre Dame from being completely torched may have created problems for the rebuild because of the amount of water needed to douse the flames. Limestone was the primary stone used to build the cathedral, but water and extreme temperatures lead to calcification and weakening of limestone. So, both the fire and the water used to douse the flames are likely to have ruined some of the stone, which will need to be removed and replaced.

Notre Dame de Paris

This is what Notre Dame de Paris looked like before the April 15 fire. What will it look like after repairs? (Photo by Matthew F. from GA via Wiki Commons)

Will a new spire, no matter its design, be made of steel or concrete? That would be the modern way, and it would mean a modern look.

If the call is to have it made of wood, as was the case in 1840, just where is the wood going to come from? The huge oak timbers that comprised the roof will need to be replaced. DeJong, who worked on a gothic cathedral in Ely, England, estimates that several hundred very large timbers would be needed for a wooden renovation of the spire and the roof trusses, in addition to an extensive number of smaller timber elements.

More than 1,300 giant oak trees were used for Notre Dame’s original roof frame; that’s the equivalent to 52 acres of trees from dense woodland. The trouble is, as Lange is quick to point out, France no longer has those kinds of forests.

One option would be to rebuild the roof frame out of fireproof concrete, which is what happened at Reims Cathedral after it was set on fire during World War I. But there is expected to be much pushback from those who want the roof they remember restored.

The more the traditionalists push to have the cathedral rebuilt to its old look, the more difficult the work is going to be and the longer it is going to take. There aren’t that many specialist workers in gothic and medieval architecture around. People who build 21st-century skyscrapers aren’t necessarily going to be able to pitch in.

There was much hue and cry when French architect Eugène Viollet-le-Duc’s spire went up 180 years ago. Expect the same, no matter what decision is made on the design.

“The conflict we are going to have now is `Should this 19th-century spire be replaced,’” Lange says. “Le-Duc was criticized in his time. People found it too gothic, said it was overdone. Others found it too fantastic, because it wasn’t an exact copy of anything, because he gave it his own twist.”

Should a 21st-century architect be told to recreate the spire that soared above Notre Dame for about one-quarter of its life? Or should the person in charge go for an entirely new look?

“It’s an opportunity for the field of architectural conservation to think about what their practice means in the 21st century,” Yu, a Berkeley doctoral candidate in art history, says. “It’s an opportunity to think about what is Notre Dame de Paris for a 21st century audience. Do we architecturally want it to look like it has 21st century accoutrements to it? Or do we want to preserve it in its 19th century form, or earlier?”

Kirk Martini, a professor at the University of Virginia School of Architecture with a doctorate from Berkeley in structural engineering, said the transept — think of the church as a cross; the transept is the short perpendicular flooring at right angles to the main floor — may prove to be Notre Dame’s greatest vulnerability in the rebuilding.

However the plans are drawn and the materials selected, there will be obstacles for both architects and engineers.

“There are so many more unknowns when you are restoring than when you are building from scratch,” DeJong says. He knew Andrew Tallon of Vassar College, who studied the cathedral extensively and did a complete 3-D laser scan of Notre Dame three years ago. Tallon died in November, but his down-to-the-millimeter scans survive.

“Having that scan is something we don’t have with a lot of historical buildings,” DeJong says. “It will make the reconstruction easier in many ways.”

As a side note, the restoration fervor that has hit Paris has reached across the Atlantic Ocean. News about the damage to one of the most famous churches in the world is helping relatively unknown churches survive their own trauma.

In St. Landry Parish, La., three black churches burned down from arson within 10 days in late March and early April. Before Monday, a GoFundMe for the churches had raised just below $50,000 in rebuilding aid. After a Twitter campaign urged people to remember the Louisiana churches amidst the devastation of Notre Dame, the total skyrocketed to $2.155 million as of Friday, more than $300,000 over the target goal.