Chapelle International, Ilot I
A UNIQUE URBAN CONDITION
The project is both the first and the last building in the Chapelle International district. It is last building to be built in terms of phasing, but it is the first architectural element visible from the trains leaving the Gare du Nord and from the main entrance to the site. It is part of the Chapelle International urban system, but it is also directly linked to a lower, more heterogeneous and older context, such as the main entrance building, the printing works and the freight hall. It is a singular
object within an overall system. This singularity is accentuated by a very pronounced public dimension. Ilot I houses a cultural facility run by the City of Paris, open to a wide range of people at different times of the day. This programme is accompanied by restaurants and commercial premises.
Figurehead
The district has a trapezoidal shape that narrows towards the south. This narrowing is expressed by a gradual convergence between the pairs of towers that form the district, culminating in their merging into a hexagonal tower, Ilot I. This geometric condition has its origins on a wider scale, in the narrowing of the
railway tracks to Gare du Nord and Gare de l’Est. This narrowing has shaped the Chapelle district and given it a unique form in Paris. This inherited infrastructural condition contributes to the singularity and identity of the district, producing iconic situations that generate an urban intensity specific to crossroads. This condition is highlighted by Ilot I’s tower. Situated at the centre of the plot, the tower benefits from a bow position, a point of articulation and convergence between several environments. The tower seeks to anchor this exceptional situation both vertically and horizontally.
Singular object within a system
One of the main design questions was how to give form to this particular urban situation? The building is not an autonomous object, but seeks to articulate the
different environments that surround it, while paying attention to the spatial qualities of the spaces it creates. Like the other buildings in the district, Ilot I consists of a tower and a two-storey plinth. A more complex relationship is sought between these two components, with gardens and terraces that allow the tower to penetrate the plinth. Two terraces also shape the tower: a large triangular terrace creates a link with the towers oriented at 45° to the north, and a smaller terrace creates a clear address towards the railway tracks to the south-west and the Sacré Coeur.
Outdoor spaces open onto the city Unlike the other, more introverted plinths in the
district, Ilot I opens up to the city. The project’s gardens and terraces are positioned outwards to establish relationships with the surrounding spaces:
- a triangular garden to the south links several programmes and faces the new public lawn
- a terrace adjoining the common room is located above the cultural centre’s reception area. It occupies the south-east corner and faces the entrance to the site and the recently redeveloped Place du Professeur-Muhammad-Yunus.
- a densely planted roof garden extends the planted street to the north and enhances the shared terrace
- a terrace in the south-west corner, provides an outdoor extension to the restaurant and faces the cultivated roof of the freight hall These spaces are carved out of the plinth with strong geometric shapes, opening them up to the city and revealing the geometry of the tower.
INHABITING THE METROPOLITAN LANDSCAPE
The relatively low context surrounding Ilot I provides the tower with an open panorama that covers the path of the Sun. The hexagon has five façades with completely unobstructed views, and one north-facing façade with a view that passes between the towers of Ilot H. As a result, even the apartments on the lower levels benefit from unobstructed views and a situation that is rare in the Parisian context. The hexagonal shape accentuates this panoramic condition, with facades that unfold to face the wider territory. The depth of the building does not allow for dual-aspect apartments between opposite sides of the building. It is therefore this panoramic condition that is exploited to offer an exceptional quality of living and provide dual aspect by using the angles of the building.
Six angles, six loggias
Loggias are covered outdoor spaces that provide protection from the elements and from views. Given the project’s highly urban and exposed position, this type of outdoor space was an obvious choice. Positioning the loggias at the corners allows us to: create outdoor spaces with panoramic qualities; absorb the geometric problems associated with the hexagonal plan with triangular loggias that subdivide the hexagon into 3 rectangles; place the loggias at the heart of each dwelling, forming an additional room that opens onto two living spaces; offer the two adjoining rooms a dual orientation. The vertical superposition of the loggias makes it possible to read the planimetric rotation and subtly fragment the volume of the tower.
Panorama - Horizontal openings
Generously sized horizontal openings accentuate the panoramic quality of the apartments. Horizontal windows with a 70cm sill allow for optimised solar gain, while also making use of the ledge below them. A desk, bookcase or radiator can sit under the window. The sill also provides privacy for the apartments and their loggias. The windows come in three widths: 150, 180 and 210cm. They are all composed of a fixed part of variable width and a narrower opening part of constant width. The openings in the loggias extend the panoramic views.
A MEETING PLACE FOR THE NEIGHBOURHOOD
The Chapelle International urban project defines urban forms composed of towers which are linked to an urban and lively lower layer formed by two-storey plinths. The plinths all share a same height and common facade principles and accommodate a variety of programmes.
Ilot I’s plinth is composed of three different programmatic entities: a municipal cultural facility dedicated to artistic practices; a series of restaurants and commercial premises; and communal spaces for the apartments. These three programmes are organised in a complementary way to provide a pleasant living environment and a place of destination for the wider neighbourhood. The project seeks to create a form of intense public life within the plinth, in contact with the public space. Each sub-entity is relatively different from one another. The project aims to offer the best spatial conditions and the most favourable location for each programme to flourish. The cultural centre is located to the east of the block, with its main entrance visible and accessible directly from the neighbourhood entrance. The commercial premises aim to anchor the building in the neighbourhood and create as much ‘mixing’ as possible between populations and age groups. The outdoor spaces, gardens and terraces, link the programmes together and open towards the public space.
Ateliers Chapelle International
The cultural centre, which occupies the south-east corner of the plinth, has a relatively complex functioning, operating both as a municipal facility but
also being made available to local associations out of the opening hours. The challenge was to create a space that combines several operating modes, maximising usage time and facilitating the sharing of spaces. It was also important to give the cultural centre a specific identity and visibility within the plinth.
The centre is located on the ground floor only. Its L-shaped plan extends from the south-east corner towards rue Mado Maurin to the north, offering three accessible facades. Two rooms dedicated to performing arts occupy the north facade. These rooms can function independently, with separate access, bathrooms and changing rooms. They can also be grouped together to form a large room by folding the movable wall that separates them. Three Fine Arts studios occupy the
east facade of the plinth. These spaces have higher ceilings, ranging from 4 metres to 6.50 metres, and benefit from diffuse northern light that penetrates through a sawtooth roof. The north-east studio has an independent access from the street, while the two other studios can be coupled into a single large room, being also separated by a movable wall. The reception area occupies the south-east corner.
The reception area and the studios’ sawtooth facade are visible and clearly identifiable from Professor Muhammad-Yunus Square and from the entrance to the site.
STRUCTURE AND CONSTRUCTION SYSTEMS
The construction systems of the plinth and the tower are distinct, as are their claddings. Our ambition was to design a low-carbon, timber-structure high-rise that would also be an integral part of the neighbourhood and in dialogue with the other buildings in Chapelle International that have strong mineral character. We didn’t want to oppose the facades of the plinth and the tower, but to apply common principles to create significant similarities despite the differences in their main materials.
The twelve-storey building is 37m high. It comprises a two-storey concrete plinth and a concrete core. The facade of the plinth is made of precast concrete
elements. The central core of the tower and most of the base walls also made of precast concrete walls. The structure of the tower and its facades are made of wood. The timber structure consists of CLT floors (160mm) and glued-laminated timber columns. Steel angles are used to fix the floors to the concrete core, and H-profiles are used to support and sew the CLT panels.
Along the facades, peripheral LVL beams encircle the building and suspend the CLT floors. The CLT floors support prefabricated timber-framed facades. All the flat roofs and the floors of the loggias are made of a composite metal floor decking.
Facades and materials
The plinth and tower share the same facade principles in terms of proportion of openings, rhythm, colour of frames and general tone, but are distinguished by their main materiality. The facade of the plinth is composed of prefabricated concrete elements, the layout of which emphasises the grid of the facade. The tower’s timber-frame facades have a ventilated zinc cladding. This choice was made not only because of the durability of this material and its low carbon footprint, but also because of its aesthetic qualities. Indeed, the position of Ilot I benefits from changing light conditions throughout the day. The light blue-grey, pre-weathered zinc cassettes reflect the light and change colour depending on the weather conditions. This reflective aspect highlights the different facets of the hexagonal tower and increases its slenderness. For the cladding profiles, we chose a large-format cassette system with bevelled edges. Its dimensions, layout and shadow gaps are similar to the prefabricated concrete elements of the plinth.
The window frames are clad in blue steel pre-frames. The timber-frame facades of the loggias are clad in white fibre cement boards, in order to match and extend the interior of the apartments. A more complex relationship is established within the gardens and terraces of the plinth where the zinc cassettes of the tower descend and give the impression that the tower is penetrating the plinth. The prefabricated concrete parts are sandblasted to reveal light blue-grey and dark-grey aggregates that interact with the zinc and blue window frames.
CREDITS
Architects : LIST (leading architect) & PioveneFabi
Structure engineers : Sodeba-Ginko
Special techniques : Facea
Cost control : Cabinet JLB
Acoustic engineer : Reflex Acoustique
