Volumes under slab

Summary :

• Genesis of the project
• Continuity and porosity, the two "Ariane's threads" of the project
• A project with the triple coloring of uses: arts, events, and sports
• Focus on the pilot project

Genesis of the project:

Historically, the Paris La Défense slab was designed to separate the functions intended for users of the district from those for technical or logistical purposes. Several tens of thousands of m² underground are however unused, representing:

• 350m long,
• 13 to 70 m wide,
• 110,000 m3,
• Variable heights between 2.5 and 12 m.

Paris La Défense has decided to launch a competitive dialogue between international architects to imagine what will become of the 20,000 m² located under the esplanade, including the emblematic "Cathedral" space of more than 5,000 m², with the aim of creating new unique places to live on the scale of Île-de-France.

The proposal by the Belgian architectural firm Baukunst was selected in March 2020. It is being rolled out gradually, both in time and space. If the project was thought out in a global way, the complexity of the infrastructures requires on the other hand to proceed step by step.

The 4 spaces concerned by the project in the long term are the following: The Cathedral: 5,000 m² / Height Under Ceiling (HSP): 6 m to 11 m L’Atelier Moretti: 2,240 m² / HSP: 4 m to 12 m The FNAC: 4,480 m² / HSP: 2.5 m to 10 m The basins: 4,600 m² / HSP: 7 mM

Continuity and porosity, the two "Ariane's threads" of the project

Baukunst is designing the project along two lines of work: • the creation of continuity between the different spaces that are now compartmentalized, • optimization of the connections between the slab and the lower levels.

The realization of these principles requires two major achievements within the framework of the project:

• a public promenade evoking the passages of Paris. Backbone of the project, this path will distribute the successive volumes and reach the Place Basse,
• a monumental footbridge in the form of a “floating” ring above the Place de la Statue. Main entrance to the volumes, it will be accompanied by a qualitative landscaping treatment. Interior gardens will be connected to the green spaces of the slab by hoppers bringing in natural light like a patio. An oculus will allow pedestrians on the Esplanade to observe the activity of the spaces below, and more particularly to offer a view of Le Monstre, the work of artist Raymond Moretti.

The interventions will aim to decompartmentalize the spaces and maximize the possible links, in the medium and long term, with other existing infrastructures such as Cœur Transport, the Parking Center Grande Arche or the Voie des Sculpteurs.

A project with a triple color of uses: arts, events, and sports

The originality of the Baukunst agency project is both to reveal the potential of these forgotten spaces while allowing them to always be able to reinvent them. This explains why the programming of the volumes is not fixed, even if prospects are emerging. A unique vestige of life in the basements of La Défense in the second half of the 20th century, Le Monstre, a work by Raymond Moretti housed in his studio, foreshadowed the development of residual volumes. The artistic dimension appears as a major axis of the staging of places. A great place of event and artistic expression will preserve the work of Raymond Moretti to make it visible to all.

Paris La Défense is currently studying a mixed program which should open up to leisure, with places to eat and well-being, as well as events and sports.

The volumes will take the form of an architectural promenade, punctuated by plays of light and shadow and artistic and event experiences.

Focus on the project

The interior life of the volumes will be signaled by the Ring, the Agam pavilion and the technical emergences of the project, giving a new dimension to the composite landscape of the slab. A walk will meander from one site to another and will provide access to the impressive volumes of the Cathedral and the Atelier Moretti where the Monster seems to be waiting for its visitors. • With the square it dominates, the Ring is both the signal for the project and the main access to the “forgotten spaces” of Paris La Défense. It will allow access to the site and the arrival of natural light in the Cathedral. From this belvedere, pedestrians can take an elevator, a monumental staircase and a double escalator.

• Punctuated by landscaped chambers in contact with the surface, the underground promenade will meander through the heart of the infrastructure up to a temporary staircase. Prefiguring a more complete wandering between the Place de la Statue and Cœur Transport, it will allow, from the pilot phase, to discover the memory and the spirit of the place.
• Visible from the promenade and accessible via an emergence, the Caveau du Monstre and the Atelier will reveal all the imagination of a district that is rediscovering itself. Their role will be particularly important in the prefiguration phase to guide the programming of future concessionaires.
• In the long term, the underground promenade will wind through the heart of the infrastructure linking Place Basse to Cœur Transport.
• Visible from the promenade, the Monster Vault and the Workshop will once again be revealed to the public.

• Illuminated, the Cathedral can also be admired from the promenade. Accessible to a limited number of people at first, it will lend itself to temporary artistic experiences with a view to future developments.
• The Agam pavilion will echo the fountain and the green spaces of the slab. This building will provide a technical function. Its upper part may be surmounted by an information screen or an artistic device illustrating the activities of the residual volumes.

The technical, functional, legal or financial architectural actions will be carried out step by step, always preserving wide possibilities of evolution.

Did you know ?

The Monster has resided since the 1970s in the dens of La Défense, and its development continued until the death of its master on June 3, 2005. Invisible to the general public today, it will be highlighted as part of the project to enhance the volumes.