A mixture of limestone and ash – similar to the materials found after the fire – was used as the material to replicate the iconic gargoyle, which was added to the cathedral’s roof during the 19th century restoration by architect Eugène Viollet-le-Duc.

Elements of Notre-Dame could be remade using the damaged stone and ashes from the fire via Dezeen
“We saw the spire collapse and thought we could propose a way to combine the old materials with new technology to help speed up the reconstruction and make a cathedral that is not simply a copy of the original but rather a cathedral that would show its layered history proudly,” Geboers told Dezeen.
Geboers believes using the materials left behind after the fire would address some philosophical problems posed by rebuilding Notre-Dame to the original design while using new materials.
“Isn’t a copy just a fake? Simply copying, pretending there never was a fire, would be a historical forgery,” he said.