With the selection of Christian de Portzamparc in 2003 for the Granite Tower project, La Défense can pride itself on having attracted one of the most influential architects of his generation. But beyond this aspect, the entire profession sees this as a sign of change. From the 1970s to the 2000s, there was a clear distinction between architects responsible for the construction of towers and the younger generation confined to residential buildings. Christian de Portzamparc managed to reconcile the two.

The Granite Tower, initially planned as an extension of Société Générale's Chassagne and Alicante towers, completes the Valmy district. Articulated in the shape of a dihedral with prismatic faces, it offers different images depending on the viewpoint. The texture of the facades, which also differs between the west and east sides, contributes to this effect. The building thus perfectly fulfills its role as the flagship of the Valmy district.

The first building in La Défense to be certified “NF Bâtiment tertiaire démarche HQE” (NF Tertiary Building HQE Approach), the Granite Tower stands as an emblem of the new generation of towers combining formal richness and technical improvement.

Directly connected to the Société Générale towers by a covered bridge, it is also served by a metal footbridge designed by Austrian architect Dietmar Feichtinger.

Trained at the École des Beaux-Arts, Christian de Portzamparc did not begin his career as a builder until the early 1970s, after devoting several years to research. He made a name for himself in 1974 with his housing complex arranged around a garden for the Petite Roquette in Paris's 11th arrondissement. In 1979, in collaboration with Georgia Benamo, he designed the 209-unit Hautes-Formes social housing complex in Paris's 13th arrondissement.
The first French winner of the prestigious Pritzker Prize in 2004, he went on to design several cultural facilities. Christian de Portzamparc is known for his focus on sculpting buildings from a theoretical volume, a concept he revisited in the Valmy neighborhood with the Granite Tower.