PB22 Tower

Architectural morphogenesis in the skyline of la Défense

In the context of a revitalization of La Défense, PCA-STREAM has imagined a complex form that grows through morphogenesis. This innovative approach, initiated with the Groupe Foncière des Régions, is at the heart of a project of demolition and reconstruction that aims for exceptional environmental performances while at the same time proposing an original organic form for the Paris skyline.

Urban dynamic of the towers

La Défense, Europe's leading business district, needed a new lease on life to remain competitive with international markets. The obsolescent nature of its property holdings and the ageing character of its concrete based urban planning, sterile and closed in on itself, pushed the government in 2006 to launch a plan to accelerate and amplify the actions engaged by the EPAD. Architectural audacity was required in replacing the most obsolete of the towers, along with the objective or harmoniously reinforcing the connections with the neighbouring communes. The objective is to restore a strong image to La Défense, an image of innovation that is in phase with contemporary environmental issues. Taking advantage of the context and the departure of its single tenant, the Groupe Foncière des Régions chose PCA-STREAM to imagine an ambitious project of demolition and reconstruction of the tower.

PB22 towers © PCA-STREAM
PB22 towers © PCA-STREAM
PB22 towers © PCA-STREAM


A logic of natural growth

The size of the plot lent itself to the construction of two towers, with the location revealing itself to be ideal for the creation of new links between Puteaux and the heart of La Défense. It particularly allowed to imagine the establishment of a strong architectural signal in the skyline. PCA-STREAM explored the idea of an innovative tower that is not limited to the endless extrusion of a standard floor: revealing complex, sensual and changing forms that depend on the position of the spectator and the light, the project deploys organically inspired forms according to a logic of “natural” growth. The general form and slenderness, quite similar to a plant, emerge from the twisting architecture and a progressive displacement of the levels.

Ground plan, tours PB22 © PCA-STREAM
Prevailing wind pressure © PCA-STREAM
Facades, tours PB22 © PCA-STREAM
Exploded axonometric view, PB22 towers © PCA-STREAM
Floor plan, PB22 towers © PCA-STREAM


A lively and diverse programme

PCA-STREAM designed two towers of different sizes, 235 meters and 145 meters, representing 90,000m² and 45,000m² respectively, with around 8,000m² of facilities and commercial spaces at the foot of the towers. This configuration, preferred to a larger single tower, allows for a larger exploitable surface and, more importantly, to embody a programmatic ambition: the first tower houses offices, a daytime activity while the second contains accommodation and a hotel, used at night. A dynamic emerges between the two towers through their base, an element of urban interlacing in public space. Environmental requirements, the comfort of the offices, integration into a skyline and a communicative function all come together to make up the genetic code of the PB22 towers. This project is also an opportunity for the agency to rehabilitate the high rise as a way of attractively densifying the building in an effort to beat urban sprawl.

PB22 towers' urban base © PCA-STREAM
Urban ground of PB22 towers © PCA-STREAM
PB22 towers © PCA-STREAM
View of upper floors, PB22 towers © PCA-STREAM
Office floor, PB22 towers © PCA-STREAM
View of upper floors, PB22 towers © PCA-STREAM


Environmental excellence as a sign

Environmental and contextual, the towers that emerge from the process avoids overblown technological devices. The architecture is based on simple strategies of protection to achieve a high level of environmental performance. The plateaus, whose depth provides access to the majority of the workspaces on the first day, stack up around a central core. The torsion and offsetting respond to the prevailing winds and the position of the sun, favouring a diversity of viewpoints. This logic of stacking generates shadows, with the long balconies acting as sun shades while highlighting the floors on a visual level. The printing on the windows evolves according to the orientation of the facades and is based on a graphic composition of variable density. This treatment that optimises sunlight and regulates thermal input, signals a controlled and rational use of the pattern. In opposition to expressive gimmicks, the architectural morphogenetic approach thus combines environmental requirements with the establishment of a strong signal in the urban landscape. It represents an architectural aesthetic that comes from an approach of research in action, mixing sustainable development, computing, science and creativity.

PB22 towers © PCA-STREAM
PB22 towers © PCA-STREAM
PB22 towers © PCA-STREAM
PB22 towers © PCA-STREAM
PB22 towers © PCA-STREAM


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Client Groupe Foncière des Régions
Program Two mixed-used towers
Location Michelet parvis , La Défense, Paris
Cost 570 M€ HT
Status Competition (2009)

Caption(s) image(s) from the page header

  • PB22 towers © PCA-STREAM