The Kimbell Art Museum’s original building, designed by Louis I. Kahn and opened to the public for the first time in 1972, has become a mecca of modern architecture. With the addition to the site of a second building, designed by Renzo Piano and scheduled to open in 2013, the Kimbell Art Foundation maintains its commitment to architectural excellence.

The Board of Directors of the Kimbell Art Foundation commissioned Louis I. Kahn as the Museum’s architect in 1966. Working closely with its first director, Richard F. Brown, who enthusiastically supported his appointment, Kahn designed a building in which “light is the theme.” Natural light enters through narrow plexiglass skylights along the top of cycloid barrel vaults and is diffused by wing-shaped pierced-aluminum reflectors that hang below, giving a silvery gleam to the smooth concrete of the vault surfaces and providing a perfect, subtly fluctuating illumination for the works of art.

The main (west) facade of the building consists of three 100-foot bays, each fronted by an open, barrel-vaulted portico, with the central entrance bay recessed and glazed. The porticos express on the exterior the light-filled vaulted spaces that are the defining feature of the interior, which are five deep behind each of the side porticos and three deep behind the central one; three of the spaces are punctuated by courtyards. Though thoroughly modern in its lack of ornament or revivalist detail, the building suggests the grand arches and vaults of Roman architecture, a source of inspiration that Kahn himself acknowledged. The principal materials are concrete, travertine, and white oak.

The Kimbell Art Museum’s exhibition and education programs have now grown far beyond those envisioned when Kahn’s building opened. The main purpose of Renzo Piano’s building is to provide extra galleries—to be used primarily for exhibitions, allowing the Kahn building to be devoted to the permanent collection––and the classrooms and studios that are essential to a full-scale museum education department. It also houses an auditorium, acoustically excellent for music, and considerably larger than the one in the Kahn building, an expanded library, and underground parking. The siting of the new building and its parking garage will correct the tendency of most visitors to enter Kahn’s building by what he considered the back entrance on the east side––directing them naturally to his main entrance on the west.