Terrace 9 - housing and office building

The Context

 

Larger territory

This set of 147 housing units is located in Nanterre on the land between the Departmental Council of Hauts-de-Seine and the Nanterre University Train Station.

The project is part of Seine-Arche development, which concerns a wider territory in line with the axis of Defense.

Taking into account the natural relief and the coexistence of various road networks which pass through, the Seine-Arche development required the upstream of colossal structures.

Aiming to attract here new populations from all over the department of Hauts-de-Seine, the urban project was designed to restore the site scale and habitability, through a series of seventeen "Urban Terraces".

The project we designed with Bouygues is part of the Terrace 9, and is situated between the tunnel of RER A and that of the A4 highway.

The block is bounded on its north and south sides by two new gardens that cover the train tunnels: the “Promenade garden” and the “Terrace 9 garden”; on the east by a monumental stair that connects the two landscapes; and on west by the boulevard of “Provinces Françaises”.

This program consists of housing, social housing, commercial premises and activities. The project is strongly constrained by the presence of tunnels, especially the train tunnel which resurfaces nearby.

The Issues

 

Urban Insertion

The site is a rectangle of 21m wide by 113m long, facing south. The project is stretched on the entire available length and consists of three separate volumes screwed on a homogeneous base.

The monumental pedestal of four levels which absorbs the declivity of the site is home to a variety of programs: social center, business center, car parks and some housing units.

The three towers of eight levels each, only contain housing units.

The base, partially embedded in the slope, occupies the entire volume of the land which consists of a series of platforms at different levels from NGF 37.80 on the south-west side, to NGF 51.85 on the north façade. The base is widened by two generous patios that allow optimal natural lighting to its top two floors dedicated to activities and housing.

The top of the basement forms a private terrace, at the same level of the Promenade garden that runs along the north facades, it ensures access to all buildings, either by walk or by the boulevard.

The base displays a regular pattern given by the identical windows, and a smooth envelope of glazed briquette. The three residential towers have different architectures.

The west building is designed as a vertical uplift of the base over seven floors. It measures 30m by 17m, and the north façade has no windows but an open patio, which includes a large tree, it naturally illuminate the stairwell and kitchens of homes.

The next two towers are identical, each one of eight square floor plans of 22.5 by 22.5 meters with central core. Their plans, includes most of the flats on the corners, which helps double orientations and stunning views.

The two towers are characterized by an architecture with shooting terraces, which withdraw in cascades to create double heights. This game of "sowing" terraces is designed to accentuate the landscape potential of buildings.

The Project

 

Architecture

A major challenge of the project is to bring a new identity to the neighborhood. It proposes a mastered architectural expression that clearly stands out from the Defense office district.

The project aspires to succeed on the big scale of urban integration as well as on the smaller scale of intimate spaces of the housing. It produces a generous environment, accessible and comfortable for the residents.

The architectural work takes into account the essential criteria of the dwellings, in terms of design efficiency, the varied views, sunshine exposure and the extension of each housing by external spaces.

The architecture of the three towers offer two highly differentiated and recognizable sequences. A rastered urban architecture for the base and west tower, and a terraced architecture like waterfalls that strengthens the landscaped character for the two next towers.

Highly exposed to the noisy boulevard and the RER, the west tower is a monolithic, framed volume. It is clearly and graphically expressed and supposed to deal with future projects of the development.

The architecture of the two towers, allows to see a stack of terraces in direct relation with the gardens that surround them. The terraces of double heights allow sizeable plantations and a great quantity of natural light to get into the interiors.

The new buildings offer an architecture that is both monumental, in response to the scale of the site and which expresses the domestic nature of the programs.

By its design, details and the choice of the materials, the project provides opportunities for the quality of living and the sustainability of the buildings 

Program

 

Even if the planned allocation for the Terrace 9 is divided into several programs, the whole ensures a single coherent expression. Our goal was to work accurately for functional quality and comfort of the housing program, distributed between the three towers and the base.

Accommodations are of varied types, ranging from studios to T5, in accession or in social housing.

One of the great qualities of the housing, is their orientation relative to the sun, unobstructed views, landscapes and walks. Most units have a double orientation, being arranged on the corners of buildings. No accommodation is uniquely oriented to the north.

In all the tree towers, the rectangular and square platforms follow the organization of living spaces as successive rows around the central core of staircases. Each floor contains an extra room for bicycles.

Each row contains a special type of space; as the servant spaces, made of bathrooms, kitchens, which are placed around the central core; the living spaces, made of bedrooms and living, occupy the periphery of each platform.

The western tower is designed as a screen against the urban nuisances of the trains and boulevard; its north façade is therefore unusable for the main living areas of the homes. The trays are arranged in U, with the same clear succession by functional rows, but in this building, the terraces are replaced by loggias, less exposed to public space and therefore more intimate. Th eliving spaces are generously sized, and all can receive disabled guests. The terraces form a final outer ring. All the units have an outdoor area.

The multiple constraints of project’s geometry, allow the realization of some atypical housing: either facing planted patios, or, for some accommodations on the second floor, overlooking a private garden. On the ground floor, which is actually a second floor on the west side, there are some T4 housing with very high ceilings.

The Facades

 

The facades are exposed respectively to the four cardinal points, they are all provided with numerous openings that extend the inside of housings to cascades of terraces, or to small hollowed loggias, which are interposed in the design of the frame.

There are two materials to dress the whole. The enameled briquette for the base and the west tower, and panels in natural aluminum for towers the two other towers.

The white lacquered steel thicknesses of the bays and loggias, define a more intimate space, between private and public interface.

Terrace 9 is a coherent whole, regardless of the type of program developed for each level. The facades assume clearly the two architectures: for the base the west tower an urban expression, for the other two towers a freer, landscaped expression.