The lobby of One Madison Avenue was combined with that of the clock tower when the east wing was originally constructed. It consists of floors and walls made of white marble and darker-marble accents, as well as a sheet rock ceiling with lighting panels, and stainless-steel doors and trim. Above the lobby are the office floors, which contain sheet rock walls and dropped ceilings; around the elevator lobbies, the floors are made of terrazzo tiles, and the walls contain a travertine veneer. The lowest six floors are served mainly by escalators and the upper floors are served by elevators. There is also wood paneling on the walls near the executive offices. A replica of the original home office's board room was built on the 11th floor of the east wing, and featured mahogany wainscoting, a coffered ceiling, and leather covering the walls. When the glass addition is completed in 2023 or 2024, it will contain event areas, a food market, and a tenants' lounge and fitness center.