From concert hall and rugby stadium to Olympic swimming pool arena in a matter of weeks, the metamorphosis of the Paris La Défense Arena is complete

Olympic swimming (July 27-August 4), Para swimming (August 29-September 7) and water polo (August 5-11) are among the most eagerly anticipated events of the Paris 2024 Olympic and Paralympic Games. But just a few weeks ago, no-one expected Paris La Défense Arena located in leafy Nanterre, to be playing host to one of the jewels of the Olympic crown.

Turning the Paris La Défense Arena of Nanterre into an Olympic venue was no easy task. Initially intended as a gymnastics venue, the indoor stadium inaugurated in October 2017, will finally host the world's best swimmers at the Paris 2024 Games. "At the time of the bid, there was a plan to build an ad hoc swimming pool in Seine-Saint-Denis, explains Denis Navizet, Event Manager of the Paris La Défense Arena. There were a number of reasons for this change of direction: in the past, Olympic pools with a capacity of 15,000 have become white elephants because they are too big. We thought about building a pool with a demountable section, but that was too expensive."

With this in mind, the Paris 2024 organisers turned their attention to existing venues capable of accommodating 15,000 people. "Paris La Défense Arena was the most reasonable and efficient choice, and the gymnastics were moved to the Bercy Arena", explains Denis Navizet.

A rugby stadium - Racing 92 is its resident club - and a concert hall in its day-to-day life, the infrastructure has nevertheless had to undergo a major transformation in order to accommodate two pools, each filled with 2.5 million litres of water. "There's an undeniable modularity and versatility that allows us to do lots of things, comments Denis Navizet. Despite this, we had to make some major alterations, such as drilling holes in the walls of the building to accommodate our TV and energy cables, and also converting a technical room into a swimming pool area, which was no mean feat."

60 days to change the Paris La Défense Arena

Nevertheless, following the handover of the keys to the arena to Paris 2024 on May 15, after the event concerts given by American superstar Taylor Swift, the technical teams managed to win their challenge. "All in all, we had 60 days to build this highly attractive swimming arena, continues Denis Navizet. We succeeded in delivering the site on time. It was a real technical and architectural feat."

To achieve this, a number of stages were necessary: fixing a large amount of equipment such as cameras and lights to the roof of the building, then laying the footprints of the pools on the ground, laying the foundations, building the pools and constructing the media stand. This separates the centre of the Arena, and therefore the two pools (training and competition).

"It took almost 20 kilometres of scaffolding to build it, it is 22 metres high and will house 1,000 media, which is colossal, says Denis Navizet. The most sensitive challenge was the co-activity between the different trades. They had to learn to work together because we couldn't work consecutively." Worker safety was also a key concern.

Pools reused in Seine-Saint-Denis after the Paris 2024 Games

To come back to the pools, they are temporary, made of stainless steel and in kit form. The Myrtha Pools teams managed to install them in 36 days. Incidentally, at 2.30 metres deep, they raised the Arena's floor above the rugby pitch.

After the Paris 2024 Games, the pools will become permanent, with one being installed in Sevran and half a pool in Bagnolet. This re-use is part of a circular economy approach, but also part of the sporting legacy, so that local residents can benefit from new facilities for learning and practising swimming.

Finally, on the night of 4 to 5 August, Denis Navizet's staff will have 9 hours in which to change the Paris La Défense Arena - which will host more than 700,000 spectators during the competition - from a swimming race configuration to a water polo configuration. "We've already planned everything", says Navizet, who is clearly not worried about the new challenge ahead.