299 TOUR PHARE, LA DÉFENSE

299
Tour Phare, La Défense
Paris, France
Competition 2006

“Projet Phare”
Architecture
Rather than produce a sculpted object-signifier or an overstated symbol, we wish to construct a building that draws on historical and natural (physical) necessity. The task is to reinvent the spirit of the place, interpreting the constraints of the site and putting cutting-edge technology at the service of a monumental form perceived as inevitable. The grounds in which the edifice will be anchored and the air into which it will rise are fundamental components of the materiality and clarity of the monumental construction.

The new La Défense tower will be an efficient working tool and an optical machine functioning from the interior toward the exterior and from the exterior toward the interior. It will be a spectacle in itself, with all the dynamics and the variety that that implies. Form, structure and materials will be inseparable in their contributions to the whole. The building will be at one and the same time an imprint on the air and an inscription in the soil, centred on the hollow footprint of a cylindrical penetration into the earth.

Depending on standpoint, the tower will appear to be slender, to have the form of a blade or that of a sail. Its location and its aerial projection in the landscape will be matched to differential treatment of its architectonic characteristics, down to perceivable details related to usage and proximity. Its simple, singular volume, which permits variations in aspect, results from the extrusion of a form provided by the site: the vast profiled triangle was established by determining the accessible anchor points. The envelope of non-reflective glass allows the structure to be seen through it: from the structural grid at the surface down to the cross girders and the core.

We have worked on the transparency of the envelope as a factor for ambiguity associating visual solidity and dematerialisation. The living, vibrant building wall stretches out like a vertical landscape striated by the succession of floors. Two other features of the building contribute to this quality of perceived extensiveness and solidity standing erect in the air: the varying densities of the structural grid and the blurring of the outer edges of its volume.

The broadening of the structural grid from ground to summit of the tower and from the centre out to its edges is dictated by physical and constructional necessity. The notching of its volume at the two eastern and western extremities results from the irregular interruption of the floors that frees up a space for vertical gardens on three levels. This relates to the possibility for the building’s users inside the tower to leave the air-conditioned environment behind and feel the variations of the outside air. For an outside observer, the vertical extensiveness of the building disappears off into the heights. It is however contained within a strictly defined form nevertheless allowing a play on the effects of varying porosity.

This erected landscape interiorises urban structure. The lift access corridors cutting right across the core are oriented in the direction of the capital’s most prominent monuments and offer striking views of the Eiffel Tower, the Sacré Cœur and the Louvre. The same axes determine the shape of the outer edges of the floors. The building is both cut through and itself cuts through. In contrast to the model of the introverted monolith protected by an outer opaque or reflective covering and set down on a plane surface, we propose an inclusive simplicity incorporating the orientations intrinsic to the urban landscape and visibly espousing the changing levels within its footprint.

The north-south orientation makes it possible to differentiate between the smooth face along the circular boulevard and the folded surface of the projection over the Place Carpeaux. In addition to the surface vibrancy this generates for the outside observer, and the visual access to the ground level it provides to the occupants of the offices, the undulation of the southern façade contributes to the building’s energy economy: it enables direct exposure of the offices to be reduced as well as producing part of the energy required for the thermal balance of the tower.

The high-rise tower, commonly known as the skyscraper, offers a “direction for beauty” as the aesthetic theoreticians would say in the eighteenth century. Emphasis is placed on the qualities of the sublime: the simplicity of regularity suggestive of infinity. We go against this norm using its counterpoint, picturesque variety, making the vertical upsurge part of a modulation of the givens of the site. The crossing of the tower at its base has been designed on a monumental scale which diffuses off into the heights. Reciprocally, the building’s aerial imprint is settled on the cylinder punched into the soil, at one and the same time penetration and the principle whereby the tower opens up to public space.
Jean-François Chevrier, 2006

FACTS

Herzog & de Meuron Team:
Partners: Jacques Herzog, Pierre de Meuron, Ascan Mergenthaler
Project Architects: Guillaume Delemazure (Associate), Kentaro Ishida
Project Team: Roman Aebi, Piotr Fortuna, Thomas von Girsewald, Volker Helm, Daniel Johansson, Daniel Kiss, Andrea Landell de Moura, Xiaojing Lu, Günter Schwob

Client:
Unibail, Paris, France

Planning:
Architect Planning: Herzog & de Meuron, Basel, Switzerland
Structural Engineering: WGG Schnetzer Puskas Ingenieure AG, Basel, Switzerland
Quantity Surveyor: Davis Langdon, London, UK
Mechanical Engineering: Transsolar, Stuttgart, Germany

Specialist / Consulting:
Elevator Consulting: Jappsen, Berlin, Germany
Safety Consulting: Veritas, Paris, France

Building Data:
Site Area: 4,600sqm
Building Footprint: 2,800sqm
Building Dimensions: Length 135m, Width 35m, Height 280m
Gross Floor Area: 180,000sqm

SELECTED BIBLIOGRAPHY

"Tour Phare" im Hochhausviertel La Défense in Paris. "Phare Tower" at La Défense in Paris.
In: Sonderdruck. Supplement: Wettbewerbe aktuell. Freiburg, Wettbewerbe aktuell Verlagsgesellschaft mbH, 04.2007. pp. 33-43.

Richard Scoffier: Puissance de l'Objet. Concours pour la Tour Phare à la Défense.
In: D'Architectures. Vol. No. 161, Paris, Innovapresse, 02.2007. pp. 20-29.

Catherine Séron-Pierre: Concours Tour Phare Unibail.
In: AMC Le Moniteur Architecture. Vol. No. 167, Paris, Group Moniteur, 02.2007. pp. 11-25.