The number of pieces in the Kimbell collection has remained at just over four hundred for forty years, but the requirements of traveling exhibitions left many works in the permanent collection unseen for significant periods of time. In 2006 the museum decided to expand. Renzo Piano Building Workshop of Genoa and Paris was hired in 2007 and in 2009 proposed an annex to the west of the Kahn Building on the lawn that constituted part of the entrance sequence to Kahn’s Kimbell.
The Piano Pavilion engages in a “dialogue” with the Kahn Building by echoing Kahn’s tripartite composition and dimensions. The deft handling of daylight is as much a signature of Piano’s work as it was of Kahn’s, though Piano’s layered roof assembly and lighting system are considerably more complicated than that of Kahn. Piano’s roof system includes louvers, photovoltaic cells for energy collection, laminated wood beams with lateral metal bracing for stability, LED lighting, and a suspended interior fabric scrim in the galleries for diffusion of daylight. Because the Kimbell planned to display art directly on the concrete walls without the linen backing panels used in the Kahn building, the concrete mix for the Piano Pavilion included titanium to imbue walls with a whitish cast. This, and the reduced need for form-ties due to the use of steel form-work, created the smooth, unblemished hanging surfaces for art. An underground parking garage was excavated beneath the common space between the two buildings. Fernand Leger’s Running Flower (1952) sits at the north end of this space.