The set of hexagonal towers with different heights has its roof in the 84 meters and involves a total intervention of about 85,400 square meters, of which 75,000 are the result of the rehabilitation and 10,400 arising from the connecting areas and expansion with a common lobby, the whole program develops, housing, offices, restaurants, cafes, an auditorium and a gymnasium.
The main actuación on these towers it is their refurbishment with a double facade that combines transparent glass areas with a second aluminum skin.
Description of the project by Dominique Perrault Architecture
The Pont de Sèvres Towers, renamed Citylights following a complete re-structuring, were built in 1975 by architects Badani and Roux-Dorlut. Bearing witness to the era’s architectural modernity, they stood high and dense in the midst of a barren urban territory. The re-structuring turned this sense of “isolation” into an asset, on a socio-economic as well as an urban level. The project we conducted is a renovation, re-structuring and an unveiling of the towers’ self-evident resources.
The site is now very well connected to the public transport system, with a métro stop right outside the building, and the Grand Paris network, whose stations are now all connected to the Pont de Sèvres Towers, placing them at the heart of the city. The towers are therefore an integral part of Paris’s recent expansion towards Grand Paris. In addition to their strong territorial impact, these elements have transformed the buildings’ morphology and mutation.
An open, sheltered campus
While the towers were originally cut off from their environment, they are now entirely and organical- ly linked to it, through a grid of pedestrian routes connecting them to the new Trapèze district. There, the wasteland of the former Renault factories has now been replaced by of ce and residential buildings, both new and refurbished. We conceived a range of spaces in order to open the project to the outside: a large plaza in front of the towers, passageways on the sides, and gardens. The project is now physically anchored in the city. The 53,000 square feet space that was created on the ground level connects the towers to their environment and roots them into the urban space of the city. With the reception areas, walk- ways and communal spaces, we are offering a new type of work environment, t for today’s world.
An unveiling process
The decision to rehabilitate large architectural projects such as this one is based on a contemporary logic steeped in efficiency and reality. These projects possess undeniable design and geometrical qualities. The hexagonal floor plan, for instance, with its central core serving floors of offices, offers 360° views of Paris and its Western suburbs. All of the work spaces receive direct daylight, and the open offices are narrow so that no more than twelve people are ever visible from any given point. The architecture of the buildings is denser than it would be, had they been conceived nowadays. Our goal with this project therefore consisted in unveiling these assets.
With their prism-like shapes, the buildings are very efficient when it comes to capturing light. Just like with optical instruments, the traditional opposition between the north and south faces of the buildings no longer applies. Sunlight shines throughout the buildings and reflects on the crystallized facades so that all offices can benefit from it, whichever face of the building they are on. This urban complex forms a prow at the entrance of the city of Boulogne, which can be seen from the highway down the hill of Meudon.
The rehabilitation process of the Pont de Sèvres Towers, while respecting their historic value, allowed for a thoroughly new structure, in line with current norms and new sustainable development performances. The name Citylights, chosen by the project management, is a perfect description of the gleaming “bracelets” of the buildings, whose lighting will be specially conceived to make them shine bright in the night sky. Light gleams on every level of the towers, in the work spaces, dining areas, auditorium and on the campus which opens out to the city below. Citylights is a luminous tower, a beacon into the city in which it is now anchored.
The Design of the Citylights Towers
The central hall: a sheltered outdoor space
The central hall, or agora, is a theatrical stage, with platforms, aisles and balconies. This generous space, filled with light on both sides, provides a uni ed physical address for the different towers, and acts as a compass to orientate visitors and employees. The interior design of this immense space reflects the architect’s stance: this Agora does not create a border between the outside and the inside, as façades flow seamlessly into the buildings. The space is consistent with the global architectural design of Citylights. It is a sheltered outdoor space, in the continuity of the towers’ environment. The duotone color palette of the Agora plays with nuances of black and white. The doors, the stair risers and the suspended metallic mesh come in different shades of grey. The wide polished stainless steel porch of the Agora acts like a kaleidoscope, reflecting natural light throughout the towers.
The metallic mesh
We rst chose to take metallic mesh away from its industrial purpose to introduce it into architectural projects with our work on the French national library (Bibliothèque nationale de France). It felt natural to us to use it for the Agora too. Just like a piece of clothing, the metal is woven on a bespoke basis: for Citylights, we designed the mesh, the stitch details, the nish… To create this unique metallic mesh for the Agora, we worked on a very large scale with 26-foot strips and invisible match. The width of the mesh embraces the hall, turning it into a generous, welcoming space.
The Albatross chandelier
The large Albatross chandelier is made up of 14 birds, with a 20-foot wingspan each. These large elements are set at different angles on a horizontal line so as to replicate the flight pattern of a flock of birds.The mix of curves and counter-curves required several sketches and models. We rst created a 2-D model on a 2-inches to 39-inches scale in order to get the angles right, then worked in 3-D to analyse the plans. Finally, we built one prototype on a 1:1 ratio, in the same material, to check on the light and the wingspan; and another one to check on the number of things as well as their size and quality. The movement of the birds depends on the weight of the metal itself, while a feeling of lightness is produced by the diffraction of light on the chandelier. A ock of birds was not our rst idea. It only came about when we determined that the lighting should use large elements in order to multiply re ections. To make the most of the light that bounces between the ceiling and the metallic doors and increase this luminous effect even more, we imagined wide metal sails with indirect lighting. These large curves brought to mind a ock of albatross, and the notions of freedom, travel, humility and generosity that these birds symbolise. Wherever you stand in the Agora, the installation never looks the same. I hope these albatross will conjure up many dreams…
The importance of light
Natural light brings architecture to life, while artificial light plays the same role indoors, as part of the nishing process. We use light to transform the spaces we create. The lighting you need to read a book or to work on a computer is dramatically different for the lighting you need to move through a building.
