Positioned at the edge of the web of train tracks, on the slab partially covering rails void for train storage, the site is inserted between this opening facing the wider landscape and what is becoming a densely built up new urban artery on the other side.
The “ribbon” plan offers an open façade in relation with the context of the train tracks, the street and the park. Thus, like a Möbius strip, the exterior and interior spaces interlock on all sides of the building, enabling easy and fluid movement and a visual continuity from the exterior and from the ground floor up to the roof. All the façades have received the same careful attention to their design, ensuring that they resemble a continuous, homogeneous and unbroken skin.
This ribbon pattern wraps around the entire building, the horizontal lines accentuating the appearance of sedimentary layers.
On each floor the levels appear to be detached from each other, an effect achieved through superposition and setbacks. These recesses result in a stratification which is further emphasized by the staggered terraces, thus avoiding overlooking views. Each office space also enjoys views into the distance and of the building’s outdoor areas, which function as breathing spaces reaching into the core of the interior layouts.
Morphological irregularities punctuate the building, breaking up its linearity. These features, through the relation between solid and void, define the building’s relation with its area, its connection with the ground, as well as its mass. The structure’s telluric character can be
appreciated differently depending on one of two possible viewpoints.
The first viewpoint is from the densely built up urban street.
The side facing the train tracks has a distinctive topography.
Working beside the train tracks is unlike working anywhere else. Here, by framing this sweeping landscape, the relation with the void which this made possible becomes a kinesthetic experience. Users can take advantage of it in their daily routines. It transforms one’s work habits into a relationship of interior–exterior, emphasized by the horizontal and vertical connection.
A continuously changing skin
The façades are composed of alternating horizontal lines, formed by glazed bays and their solid window aprons. These ribbons vary according to their height. The lower levels, where light is restricted, have full height openings onto the balconies, whereas the upper floors, naturally
benefiting from more light, have a lower apron offering panoramic views onto the city.
The building opens broadly onto the city. The transparency of the lobby on two levels enables everyone to enjoy the site’s incredible geography. This lobby, designed to match the scale of the building is a bright and airy public space that orients the view onto the panorama
of the train tracks, which the terrace, designed as a belvedere also overlooks.
The lobby uses a simple selection of materials. Vals stone laid lengthwise covers the floor and the interior of the staircase like the lining of a garment. The metal structure composed of columns creates a spectacular space with a height of eight meters. These cruciform metal structural
elements imbue the space with a subtle vibrancy. The treatment of the base of the columns hides their spring supports. Technical elements also disappear underneath the continuous material surfaces.
Fluidity of usage
A reflexion on the domestic ambiance of work spaces led to an alternative design for circulations encouraging friendliness and spontaneity. Thus, exterior and interior spaces have been interwoven across all façades of the building, facilitating a smooth flow from one area to the next and ensuring visual continuity from the ground floor up to the roof, where a hanging garden offers an entirely new kind of work space.
The system of ribbon windows on each floor of the building varies, increasing the penetration of natural light, which is greater than average on every side (glazed from 43% in the upper floors to 93% on the lower ones). For optimum comfort and real contact with the outside, every other window opens to the outside for natural ventilation.
In addition, all sides exposed to direct sunlight are equipped with exterior blinds, which are connected to the BEMS.
The absence of air-conditioning is compensated for by an exposed (varnished) heat insulation slab in the offices. Heat absorbed during the day is evacuated to the exterior, outside office hours, via water cooled by adiabatic drycoolers. In winter, this system contributes a great deal to the buildings heat supply by circulating water at a temperature of approximately 27°C. Users can adjust the temperature by means of natural convection baseboard heaters installed every other section of the framework. This system generates no ventilation energy. Utility networks are distributed under the false floors to maximize transfers between concrete and the volume to
be cooled during the summer and thereby take maximum advantage of inertia of the structure’s inertia.
This energy concept was chosen for the quality of the thermal transfer between warm water and concrete, which is superior to that between air and concrete. Furthermore, the possibility of vaporizing this water on high-temperature nights to cool the batteries of the adiabatic dry coolers meaning the system can remain in use even during the most sensitive periods.
This system is completed with ceiling fans custom made for this operation, which made it possible to increase their thermal performance and reduce noise while also rendering them more aesthetically pleasing. Under the concrete slabs, made-to-measure acoustical slabs allow for the layout of offices according to a standard framework. The false floors allow for the regular
installation of the technical elements required for a functioning office building and also allow the height of the floors to rise up to three meters beneath the slab.
Since its founding in 2008 by Frédéric Chartier and Pascale Dalix, the ChartierDalix office has delivered some fifteen buildings.
Laureate in 2017 with the Nouvelle AOM (Franklin Azzi Architecture and Hardel & Le Bihan Architectes) for the project “Demain Montparnasse,” the office masters a broad range of commissions and programs, both public and private.
For the last several years, the research department of the office has undertaken work on the integration of the biosphere in architecture.
The many investigations and analyses undertaken by the office, and the diversity of responses received concerning its buildings form an ensemble that reflects the evolution of contemporary living conditions. For this young team, architecture is envisaged as a built system combining the integration of the biosphere and poetry.