In 2006, the Kimbell Art Museum commissioned Italian Architect Renzo Piano to design an addition to the museum. Piano chose to separate the addition from the main building by constructing it on the west lawn of the property. The new building still preserves part of the lawn and pays tribute to the original building by matching the scale, materials, and use of light. Part of the building has been built underground and is below a green roof.
The main galleries of the building feature a glass roof system sitting above laminated wood beams and concrete columns. They also feature a breathable floor where the entire floor is a part of the heating, ventilation, and air conditioning system of the building. Also situated beneath the glass roof, is the buildings lobby, which is recessed from the main walls of the galleries. This is similar to the way the original building is laid out. The portions of the building on the west side housing the education areas, the auditorium, and one art gallery are beneath a green roof. Light wells allow light into the classrooms and into the auditorium.
Parking for the museum was constructed between the two buildings and beneath the lawn. This assured that as much green space as possible was preserved on the site. New trees have been planted in the same locations in the lawn to re-establish the planting done when the Kahn building was constructed in 1972. Kahn's landscape design has been retained or replanted as much as possible.