“No space, architecturally, is a space unless it has natural light.”

— Louis I. Kahn

A person’s experience of an architectural space is shaped by many factors, including its scale, proportions, plan, and use of materials. In many buildings, and especially at the Kimbell Art Museum, light performs a crucial role—illuminating the space and creating a mood. In his teachings and designs, Louis Kahn constantly stressed the importance of light in relation to structure. Natural light, “dynamic, ever-changing,” he preferred above all other sources of illumination.

Many museum designs primarily rely on artificial lighting to prevent direct sunlight from damaging priceless and delicate works of art. Kimbell director Richard Brown, however, felt that natural light should be used to illuminate museum spaces so that visitors may be able to relate to nature and the effects of changing weather while inside the Kimbell. This type of lighting also enables the visitor to see the work of art more similarly to the way it would have been viewed by its creator, under conditions of natural light. Kahn and Brown met well on this topic, which became the inspiration for Kahn’s concept of the cycloid vault with “narrow slits to the sky” that allowed natural light to enter and transform the space. However, the works of art are not illuminated entirely by natural light—lamps bolster the daylight to give a mixture of natural and artificial light that is ideal for viewing works of art.

In order to allow light to enter the space without endangering precious artworks, Kahn envisioned a metal “reflector” or “shield” that would be placed directly beneath the skylights to reflect sunlight onto the smooth, gray, curved surface of the vault. As if by magic, the light would transform the surface, creating a silvery luminosity that filtered down and filled the space below without harming the Museum’s collection. Lighting consultants worked with Kahn to devise gull-wing shaped reflectors that are now installed in the Kimbell. These “natural light fixtures,” made from pierced aluminum, were curved to simultaneously reflect and filter the Texas sun. For works of art that require very low levels of light (drawings or Asian scroll paintings, for example), black felt can be used to cover the skylights to further reduce the amount of light reflected into the gallery.

Kahn incorporated slender lunettes at either end of each vault for more light. The lunette also acts as an important element that separates distinct parts of the structure and is, in turn, shaped by those parts. Its underside echoes the cycloid, while the topside is shaped by the concrete shell that thickens at its apex. Therefore, the topside of each lunette expands at the bottom and becomes thinner at the top. Light slots run along the entire bottom length of the vault to allow indirect sunlight to enter Museum spaces. Kahn also designed three courtyards, named after the kind of light that he anticipated that their proportions, foliation, or sky reflections would give: Green, Yellow, and Blue Courts. Visitors can easily recognize the Green Court, with its vine roofing, or the Blue Court, with a splashing fountain that reflects sky and water off its travertine enclosure. The large Yellow Court is situated next to the Kimbell’s conservation studio.