Notre Dame’s restoration enters a new phase as architects envision a new mix of the ancient and modern

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At Notre Dame Cathedral in the week before Christmas, hundreds of workers toiled around the midpoint of Paris’s most famous sacred building, where a 600-tonne, 100-metre-high temporary structure was growing to support the work of reconstruction – including bringing a new spire up toward the sky.

It has been 3½ years since the fire that devastated Notre Dame, the touchstone of French cultural identity that stands on the Île de la Cité in the heart of Paris. Public officials plan to reopen the cathedral in December, 2024, and complete the restoration the following year. It’s a remarkable rebirth for a structure that only recently seemed on the verge of collapse.

“The work is proceeding extremely well,” said Michel Picaud, president of the charity Friends of Notre Dame de Paris. “What has been decided is to restore the cathedral to the state she was in before the fire and … the schedule seems very solid.”

When the fire struck, the 850-year-old building was already in the middle of a restoration and “in a very bad state,” Mr. Picaud explained. His group was founded in 2016 to raise funds for that project, “but our scope of work expanded pretty significantly after the fire,” he added wryly.

The fire began in the attic, nicknamed “the forest” for its massive timbers from ancient oaks. These fuelled a blaze that attacked the spire, sending it crashing through the roof. It took 18 months for officials to confirm that the cathedral’s walls would be able to remain standing.

Already, part of the interior has been fully restored. Construction on the roof and the spire will begin this year To that end, more than a thousand oak trees were harvested from across France, each of them at least a metre in diameter and some 18 metres long. Some came from the forest of Bercé, which once belonged to the kings of France.

The current church-building project follows in a 1,700-year tradition on the Île de la Cité. Between the fourth and the 12th centuries, five churches were built on the island, by then home to the French monarchy. In the late 1100s, Paris bishop Maurice de Sully decided to create a new cathedral that would rival St. Peter’s Basilica in Rome. An anonymous master mason began the design of the structure, and construction started with limestone quarried nearby, along the banks of the Seine.

The vision that emerged was a highlight of French Gothic architecture. A complex structure of limestone members spanned the volume of the cathedral with rib vaults, while exterior supports known as flying buttresses carried the weight of the roof down to the earth. This eliminated the need for many interior walls – human ingenuity delivered space and light suitable for worship.

The building opened in 1182, but the whole structure was not completed until 1260. From the sanctuary it stretched westward, spanning out north and south in two perpendicular transepts – creating the form of a cross when seen from above. The building culminated to the west with its main façade, which once faced an intricate medieval streetscape. Twenty-eight statues, the “gallery of kings,” march across the wall above the main doors.

The cathedral changed significantly in the 18th and 19th centuries, following changes in taste, liturgy and politics. Its original spire was removed in 1792. It was heavily vandalized during the French Revolution. In the 1860s, architect Eugène Viollet-le-Duc led a restoration that included a reconstruction of the spire – thinner than the original – and other changes that proved controversial.

After the 2019 fire, there was much debate over how to restore the building. French President Emmanuel Macron suggested replacing the spire with a “contemporary architectural gesture.” But this idea was abandoned; the spire will be rebuilt to the design of Viollet-le-Duc.

However, the area around the cathedral is also changing. Earlier this year, the city of Paris held an international design competition to reconsider the public spaces around Notre Dame. The winning team is led by Belgian landscape architect Bas Smets. (Mr. Smets and his team are also working on the Block 2 proposal for Canada’s Parliament Buildings.)

For Mr. Smets, the importance of the project is clear. In an interview, he quoted Victor Hugo in saying that the Île de la Cité is the cradle of Paris. “It’s been alive for 800 years, and it’s witnessed a city that changes – the redevelopment by Haussmann, the Pont Neuf. So this project posed the question: What kind of Paris do we want to build for the future?”

Two answers: an awareness of the effects of climate change, “and a new collective idea of public space,” Mr. Smets said, “on this place which is for the most part accessed by tourists.”

The project, scheduled to begin construction in 2024, will add hundreds of new trees to the main square and supply a trickle of water across the paving stones to reduce the ambient temperature. Visitors to the cathedral will be able to line up more comfortably on hot days – which will, Mr. Smets points out, become more common. The designers are rethinking green space to the east of the cathedral; the banks of the Seine, to its south; and an underground parking garage beneath the square. The latter will be converted into a visitor centre.

“We have been thinking about the approach to the cathedral,” Mr. Smets said. The front façade was designed to be seen from bottom to top. “The architecture is meant to draw your eye upward toward heaven,” he added. “Now, as you climb the stairs, you will be taken back into history and see the cathedral as it was intended to be seen.”