The expansion will now allow the museum to display most of its permanent collection while also hosting exhibits. In the past, the museum has been forced to put much of its permanent collection in storage when it hosts special exhibitions.
Lee estimates that the $135 million expansion triples the gallery space available for the museum's permanent collection.
That permanent collection ranges from Egyptian antiquities to European art from the Italian Renaissance to Asian, African and pre-Columbian objects. The collection includes works by Caravaggio, Poussin, Velazquez, Rembrandt, Monet, Cezanne, Picasso and Matisse.
Piano has designed several museums, including the Centre Pompidou in Paris and the Nasher Sculpture Center in Dallas. Kahn, who died in 1974, also designed the Yale University Art Gallery and Yale Center for British Art.
The Kimbell is currently hosting an exhibit of modern works from the Art Institute of Chicago. The exhibit titled "The Age of Picasso and Matisse: Modern Masters from the Art Institute of Chicago" features almost 100 works, including those by Picasso and Matisse and runs through Feb. 16. The Kimbell is the only venue for that exhibit.