Part of the reason Notre Dame is still standing is apparently a smart design choice by its medieval architects

Firefighters douse flames billowing from the roof at Notre-Dame Cathedral in Paris on April 15, 2019.

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Firefighters douse flames billowing from the roof at Notre-Dame Cathedral in Paris on April 15, 2019.
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HOMAS SAMSON/AFP/Getty Images

  • The original architects who built Notre-Dame Cathedral in the 12th century deliberately designed it to survive a major fire, an expert has said.
  • The large space between the ground and the base of the spire was “a kind of fire door between the highly flammable roof and the highly flammable interior,” according to Dr. Tom Nickson, senior lecturer at London’s Courtauld Institute.
  • So far, French billionaires and companies have pledged nearly $1 billion to fund repairs. President Emmanuel Macron said Notre-Dame will be rebuilt “even more beautifully.”
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Early Medieval builders deliberately designed Notre-Dame Cathedral to survive a catastrophic fire like the one this week, an expert said.

Dr. Tom Nickson, a senior lecturer in medieval art and architecture at London’s Courtauld Institute, said the decision likely saved it from burning to the ground on Monday.

Nickson told The Associated Press that the cathedral’s cavernous stone vault – the space between the nave and the bottom of the spire – “acted as a kind of fire door between the highly flammable roof and the highly flammable interior.”

Nickson said this was a conscious design choice, and would have been in the minds of the builders when they constructed Notre-Dame for the Bishop of Paris, Maurice de Sully, in the early 1100s.

The fact the blaze did not spread from the spire to the rest of the cathedral allowed firefighters to save priceless relics located on the ground floor – including the crown of thorns purportedly worn by Jesus on the cross, and the Tunic of Louis IX.

The Holy Crown of Thorns.

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The Holy Crown of Thorns.
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REUTERS/Philippe Wojazer

While the original builders may have tried to mitigate any chance of fire damage, using large quantities of wood was inevitable in Middle Age construction.

Notre-Dame spokesperson Andre Finot told media that the wooden interior of the cathedral is likely beyond saving after the fire.

Chris Marrion, fire and disaster management consultant, told INSIDER’s David Anderson: “The wood trusses, the roof decking, for instance, just regular interior finishes throughout these buildings that are a lot of times of wood.”

Marrion said restoration works – which Notre-Dame was undergoing when the fire started – can often trigger disasters like the one which struck.

Renovators had been working on a $6.8 million project to sure-up the church spire, the area where the fire started.

“We have, you know, a lot of temporary electrical, temporary lighting in those. We have hot works going on – cutting torches and welding operations and those types of things,” Marrion said.

“So, you know, there’s a fair amount of new ignition sources that are introduced there on a temporary basis.”

Flames and smoke are seen billowing from the roof at Notre-Dame Cathedral in Paris on April 15, 2019.

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Flames and smoke are seen billowing from the roof at Notre-Dame Cathedral in Paris on April 15, 2019.
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PATRICK ANIDJAR/AFP/Getty Images

Firefighters in Paris said that the renovations could be linked to the blaze, though the cause is still being investigated.

French billionaires and businesses collectively donated €800 million ($902 million) to repair the landmark.

President Emmanuel Macron gave a televised address on Tuesday in which he said: “We’ll rebuild Notre-Dame even more beautifully.”