The Île-de-France project was initially entrusted to Paul La Mache and was to resemble a group of low, pyramid-shaped buildings. However, this project was abandoned, leaving the new architects, Roger Saubot and François Jullien, with a restrictive master plan. The building, located between the Atlantique tower and the Ève tower, could not exceed 32 meters in height. The architects therefore adopted the principle of building on stilts, combining it with facades typical of 1980s buildings in blue-gray tinted glass.

The concrete framework remains visible. Like stilts, the columns are very prominent.

The Saubot et Jullien agency was founded in 1964 by Roger Saubot (1931-1999) and François Jullien. The two architects specialized in the construction of high-rise commercial buildings, for which they partnered with major international names. In 1969 and 1978, they designed two buildings with the American firm Skidmore, Owings and Merrill: the Areva Tower and the Sgam Building.

Like Henri La Fonta, Roger Saubot and François Jullien established themselves as the leading architects of La Défense, working on a total of 11 projects and participating in the transition to more energy-efficient buildings.