Empyrean House

The Empyrean House (casually known as the Silver Tower because of its metallic coloration) is a large building, a skyscraper located in the city of Paris on the planet Earth, at the center of the United Federation of Planets. The Empyrean House is commonly known as the home of the Federation government offices, including that of the President of the United Federation of Planets.

Surrounding a central courtyard that hosts government and presidential personnels' rest time and public ceremonies, the main body of the Silver Tower is 30 stories tall, with a section that rises to a 100-story tall spire. The lower floors of the Empyrean House have a number of offices and facilities that are open to the public, including auditorium spaces, exhibits and public relations centers. Many upper floors contain secured spaces that are home to key leadership of Federation security, defense, and other public services.

The President's primary office, the Red Room, is situated on the 30th floor, and provides a scenic view of the Eiffel Tower. The President has the option of maintaining family quarters in the building, either on the 30th floor or elsewhere in the spire. 

Background
Presumably, this building was the presidential office complex from and.

In a seeming contradiction, this RPG-sourced reference describes this as the President's optional living quarters, unlike Pocket Books novels that show the head of the UFP residing at the Palais de la Concorde. However, this isn't a complete discontinuity, as the RPG states that the President's quarters at Silver Tower are optional, meaning that alternate residences are also possible and likely.