"“The most modern and ecological material today is wood,” Wirth said.
He said the cathedral is still at risk of collapse after a fire struck the cathedral in April, destroying the roof and spire and damaging the windows and vaults. He said alternative materials to wood might have resulted in further damage to the cathedral.
“The cathedral has been there for 800 years. Had it been built in concrete or steel it would not still be there,” he further added.
“Even with all the (chemical) protection treatments, given the intensity of the blaze... the steel would have held for half an hour and then it would have twisted, pulling on the walls and everything would have collapsed.”"