Notre Dame: Skills shortage could delay rebuilding project, says UK architect who helped restore Windsor Castle

British expert warns of high demand on ‘skilled specialists’ as French government launches international competition to replace spire

A leading British architect who helped restore Windsor Castle after it was a ravaged by fire has said a shortage of building specialists could impede Emmanuel Macron’s target of rebuilding the Notre Dame within five years.

As bells rang across France in commemoration of the blaze, a French government official warned the Paris landmark would have burned to the ground on Monday night in a "chain-reaction collapse" had firefighters not moved as rapidly as they did.

A fund set up to rebuild the fire-ravaged Notre Dame Cathedral in Paris was fast approaching €1bn (£870m) as donations continued to pour in from billionaires, corporations and ordinary citizens.

The French president wants the cherished cathedral returned to glory in time for the Paris Olympics in 2024 following Monday’s devastating blaze, but some have already cast doubt on the ambitious deadline.

Francis Maude, director at the Donald Insall Associates, told The Independent it would be difficult, but he believes it can be done.

“It’s ambitious, but I think it’s achievable if things go well,” said Mr Maude. “One of the things that makes me think it can be done [in five years] is the restoration of Windsor Castle. It shows projects of considerable magnitude can be undertaken in that sort of time frame.”

However he warned that the “specialist labour force” needed for such a complex and delicate operation was in short supply, and delays getting the right people could hamper the project.

“What you need is an expert project manager who would be able to identify the materials that are in restricted supply,” he explained. “The same applies to specialist labour force which is needed for the stone carving, the lead on the roof, repairs to the stain glass windows and for the internal decorations and other finishes.”

“There are a number of other big, high-profile projects which will take a large part of the labour supply needed, the specialist craftsmen – there’s the restoration of the Palace of Westminster and of the Canadian parliament in Ottawa. It’s going to place a certain demand on the skilled specialists that there are."

Mr Maude added: “One would not expect people to down tools, as it were. If they’ve already been engaged in one project, you would expect them to be committed to that project.”

The warning came as the French government announced an international design competition to replace the cathedral’s iconic spire, destroyed during the fire.

Edouard Philippe announces competition to replace Notre Dame spire (AP)

Prime Minister Edouard Philippe suggested on Wednesday that architects may be able to completely remodel the spire – added to the cathedral in the 19th Century as part of renovation project led by French architect Eugene Viollet-le-Duc.

“The international competition will allow us to ask the question of whether we should even recreate the spire as it was conceived by Viollet-le-Duc,” he said. “Or if, as is often the case in the evolution of heritage, we should endow Notre-Dame with a new spire.”

Even Mr Philippe acknowledged that it would be difficult to restore the whole building in just five years. “This is obviously an immense challenge, a historic responsibility,” Mr Philippe said.

Prominent French conservation architect Pierluigi Pericolo told Inrocks magazine it could take triple that time. “No less than 15 years ... it’s a colossal task,” Mr Pericolo said.

Mr Pericolo worked on the restoration of the 19th century Saint-Donatien basilica, which was badly damaged by fire in 2015 in the French city of Nantes. He said it could take between “two to five years” just to check the stability of the massive cathedral that dominates the Paris skyline.

“It’s a fundamental step, and very complex, because it’s difficult to send workers into a monument whose vaulted ceilings are swollen with water,” Mr Pericolo added. “The end of the fire doesn’t mean the edifice is totally saved.”

Debris inside the cathedral after the 12-hour battle to extinguish an inferno that claimed its spire and roof (AP)

French companies Total and L’Oreal have promised to each donate €100m (£87m) euros to the restoration, while the billionaire families who own LVMH Group, Kering and L’Oreal pledged a combined total of €500m (£435m).

The French government is gathering donations and setting up a special office to deal with offers of assistance.

Despite extensive damage, many of the cathedral's treasures were saved, including Notre Dame's famous rose windows, although they are not out of danger.

Paris firefighters' spokesman, Gabriel Plus, said that even though they are in good condition, a "threat" continues to the gables, or support walls, because of the heavy stone statues perched on top of them.

"The roof no longer holds (the gables) up. They are holding up all by themselves," he said, adding that some statues must be removed to lessen the weight on the gables.

Scaffolding that had been erected for a renovation of the spire and roof must also be properly removed because of its weight and because it is now "crucially deformed", he added.

The cathedral is still being monitored closely by firefighters and experts to determine how much damage the structure suffered and what needs to be dismantled to avoid collapse.

A plan to safeguard the masterpieces and relics was quickly put into action after the fire broke out. The Crown of Thorns, regarded as Notre Dame’s most sacred relic, was among the treasures quickly transported after the fire broke out, authorities said. Brought to Paris by King Louis IX in the 13th century, it is purported to have been pressed onto Christ’s head during the crucifixion.

The cathedral’s famous 18th century organ that boasts more than 8,000 pipes also survived. Some of the paintings and other art works are being dehumidified, protected and eventually restored at the Louvre.

Notre Dame’s rector, Bishop Patrick Chauvet, has said he would close the once-functioning cathedral for “five to six years” acknowledging that “a segment” of the near 900-year-old edifice may be gravely weakened.

Addditional reporting by agencies