POLARIS
The development of the Brossette site completes the transformation of the Boulevard Vincent‐Gâche. It is the largest construction site ever completed on the island of Nantes. Occupied formerly by warehouses of a sanitary manufacturer, the 1.5‐hectare plot facing the Loire, hosts six new buildings with mixed use, including a panoramic tower of 18 floors.
The project, sitting at the crossroads of urbanism and architecture, offers a methodological alternative to the typical urban factory of ZAC, opposing the logic of prescriptions to that of dialogue and sharing.
Polaris is the result of a work of designers gathered in the form of a group sharing the belief that architecture is at the service of the city. Workshop after workshop, the group negotiated each of the decisions at the scale of the building and that of the district.
As a continuation of the work of UAPS and Marcel Smeth (in charge of urban project management on the island of Nantes), LAN designed the mass plan and the major urban principles of the operation, and acted as representative of the group composed of Abinal & Ropars and Atelier Stéphane Fernandez. The agencies worked together to adjust forms and programs with many goals: transforming high density into quality, defining a coherent public space and asserting a clear and legible urban identity.
The site is at the intersection of several formal systems: buildings dating from the 1970s condominiums based on the model of large housing projects or “estates,” an office complex, which was never entirely completed, with courtyards and gardens ; and the intervention of Alexandre Chemetoff, architect of the first phase of urban renewal of the islands. In this heterogeneous context, a synthesis in which the new Polaris island plays a pivotal role has emerged. The layout of the buildings is based on a frame cut into strips; which crosses the parcel from one end to another and offers new paths to enhance the proximity of the heart of the site with the river bank. Formed by the construction of buildings, interiorities emerge and are organized in squares, terraces or gardens, polarizing the uses according to specific themes, in response to the needs of the public space.
Polaris is home to a campus of over 10,000 square meters in which the international school of hotel and tourism management Vatel has chosen to establish a new institution. It includes classrooms, a restaurant, a brasserie and a pub open to the public, as well as a student residence with 300 apartments. The program also includes 250 housing units, nearly 6,500 square meters of office space and 600 square meters of activity spread between the different blocks of the operation. In addition to the alignment of floors from one building to another, and the regularity of the openings composing the facades; each common space – regardless of its position on the building site to which it belongs ‐ reaches the same level of a distant and unobstructed view of the old city skyline.
Although the parcel is entirely private, all outdoor spaces are open to the city. The neighborhood, which has become entirely pedestrian, is crossed by a central alley. It is the spine of the island and leads to the heart of the project: the forecourt, of the tower renamed "360°View", which was turned into a public square. Four huge poplars interact with the facade dressed in brushed aluminium. The facade reflects its environment during the day and comes alive at night in a set of transoms set in motion by perforated shutters. Viewed from the south, the building closes the perspective. From the river on the north, it sets the tone of the realization.
Plots 1‐4: 144 units
Located at the south‐west corner of the plot, plot 1 marks the entrance of the Brossette island from Boulevard Vincent Gâche. It presents two scales: the pedestrian scale and that of the wider boulevard, main longitudinal artery of the island of Nantes. Welcoming 65 units as well as a local activity on the ground floor, this plot is divided into two parts: the base (RDC‐R + 5) and the high volume (R + 6‐R + 14). The upper part is shifted from the lower one to the north and east, offering a shared terrace for the inhabitants of the building.
The accommodations have many orientations, each comprised of a loggia, a true extension of the outside stays. Inside, the tasteful design of the apartments, particularly through the quality of natural lighting, the sequencing of spaces and the multiple views, creates nuanced atmospheres in relation to the diversity of neighboring urban situations. In a sustainable approach, a change in housing is possible by transforming loggias into buffer zones.
Apart from the withdrawal play, the four facades are similar in their composition. The regularity and size of the openings form an image of the building that does not clearly indicate the assignment. This rhythm is challenged by the random arrangement of loggias, which brings depth to the overall image of the building. All facades are made of brown tinted concrete; a special attention has been given to its expression.
At the north end of the Brossette island, on the edge of the eponymous square, plot 4 is the point of entry and completion. Seen from the Loire, its volumetric announces all the elements that are then available on the site; Conversely, seen from the south, this architecture completes the succession of spaces and connections characterizing the Brossette island. The volume is refined as it rises, responding to poplars bordering it and neighboring buildings, to harmonize the relationship. The carving also allows the plot 4 to hold its role of signal and to close perspective from the major axis of the site.
Comprising 71 units as well as an activity room on the ground floor, the tower is divided into three superimposed volumes; their shift forms private terraces, open to the privileged context. Most housing are decorated with generous loggias and external extensions of living rooms. The height of the tower offers panoramic views on The Loire, the historic city center and the island of Nantes. The frame of the façade is formed by the alternation of horizontal and vertical solid bands with partially perforated parts, sifting the natural lighting. The brushed aluminium gives a homogeneous image to plot 4 which reflects its context. At night, the game is reversed; the building comes alive through the activity inside.
Plots 3‐5: Student Residences and Vatel Campus
Located along the new route and the Cours Brossette axis, Plot 3 is one of the buildings that defines the main square of the island. In the general composition of the mass plan, the alternation of voids gives shape to the sequence of volumes and sets the limits of the footprint of the plot.
Mixing housing, business premises and tertiary, the program is divided into two overlapping entities: almost independent, each component is adjusted to the requirements of its program. The lower part is occupied by the School of haute cuisine and hotels of Nantes with its restaurant, brasserie, and storage. The upper part is dedicated to a Residence‐Service for Students. Grouping the collective entities of the CSR, the R + 4 becomes a terrace on the city. Programmatic cutting is noticeable on the facade: each entity is formed of a glazed level surmounted by 3 floors dressed with metal blades serving as brise‐soleil. The gap between 2 blades maintains a complete transparency from the inside, while their thickness allows to control the light and to create a changing external appearance. This envelope reinforces the precious and monumental character of the building, while the effect of transparency and light increases the user‐ friendliness of the spaces and the user’s comfort.
Balancing the composition on either side of the Cours Brossette, the plot 5 has a morphology resulting from the layering of two volumes. Their offset (16 meters to the west and 4 to the east) marks the distance from the large complexes of the neighboring city and the other buildings of the operation.
The 4 floors of the base include the Vatel café, access to CSR, parking and 2 floors of the residence. The high volume includes the rest of the residence’s units.
The design of the facade resides on the repetition of a single element: the bay. The regularity and the size of the openings make it possible not to reduce the image of the building to the only expression of its function, and gives it a more urban aspect. The work on the frame of the void, on the rigor of concrete ribs, on the depths of field, continues the play of transparencies, reflections and visual breakthroughs, and contributes to the creation of a building in dialogue with its external environment. A Particular attention has been given to the expression of materiality. All the facades are made of sand‐colored concrete, in harmony with the adjacent buildings. Extending the basic module and substituting the perforated tinted bronze sheet for the glass, stages 1 and 2 make a visual transition between the large windows of the DRC business premises and the R + 3 housing.
