Included in Émile Ailliaud's master plan for the Tête Défense sector in 1972, Élysées Défense is one of the most iconic buildings of the third generation. Originally intended to be a hotel, the building ultimately houses offices.

A true horizontal tower, it rests on the roof of Les Quatre-Temps. Its architecture requires a specific structure with different levels. Despite the building's thickness (43 m), two covered atriums allow light to reach all the tropical gardens located in the middle of the building, which serve as a thermal buffer. Widely used in the United States, the glass atrium provides generous lighting. They are particularly popular in museums, hotels, and large public buildings.

In 1995, a change of ownership led to the renovation of the building. The west gable of the building, the main façade, is clad in light-colored stone that contrasts with the bluish tones of the curtain walls.

In March 2016, Window underwent a restructuring project. The work included 40,000 m² of office space as well as restaurant areas.

The fully transparent façade was designed to offer multiple views of the outside.

The building revisits the standards of office real estate: flexible, fluid, mixed-use, technological, adapted to new ways of working (from the most integrated to the most nomadic), offering connected spaces for socializing (catering, services) and collaboration, and compliant with major international standards.

The project has a threefold objective:

• to reinvent commercial real estate,
• to offer large French companies a space with global reach, and
• to help shape what La Défense will look like in 20 years.

The upper terrace, featuring shops and restaurants, is accessible to all, giving the impression of a balcony overlooking the city to create a new experience of La Défense.

The Saubot 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 and collaborated with numerous international firms, most of them American. In 1985, they designed the Bouygues Construction headquarters in Guyancourt, in partnership with Kevin Roche and John Dinkeloo.

In association with the renowned Skidmore, Owings and Merrill agency, they participated in the Fiat Tower project in 1964 (renamed the Areva Tower in 1979). They established themselves as the architects of La Défense and worked on 11 projects, ensuring the transition to more energy-efficient and better-lit buildings (Total Coupole, France Télécom, the Veritas offices, etc.). Roger Saubot and François Jullien then continued their careers working for the Disney Festival at Eurodisney in 1992 and the American Center, now the Cinémathèque Française.