It has been nine years since the completion of the Yale Center for British Art's previous phase of conservation, which focused on interior refurbishments, improvements to visitor amenities, and system upgrades. World-Architects visited in 2016 and was impressed by nearly every aspect of Kahn's posthumous masterpiece, especially the galleries on the fourth floor that are illuminated by the skylights and look onto the generous Lobby Court and Library Court. While we didn't have a frame of reference then for how the conservation work compared to before conditions, our second visit last week allowed us the ability to track changes. Needless to say, the changes were barely perceptible, limited to reintroduced elements, upgrades to new materials and technologies, and unintended effects arising from renewed care and maintenance. This latest visit was similar to 2016, when architect George Knight of New Haven's Knight Architecture, who also worked on the latest phase, pointed out that differences have been slight because the building had been so well maintained over the years.

Past, current, and future conservation work is based upon comprehensive research that was published in 2011 as Louis Kahn and the Yale Center for British Art: A Conservation Plan. That document was done by conservation architects Peter Inskip and Stephen Gee under then YCBA deputy director Constance Clement. Martina Droth, the current Paul Mellon Director of the YCBA, has been in that role since January 2025.

Louis Kahn, known for poetic statements, once wrote, “Design is form-making in order.” That he followed this dictum is apparent in the barrel-vaulted bays of the Kimbell Art Museum, for example, and other projects, including the 20x20-foot (6x6m) structural bays of the YCBA. The square bay determines the rectangular floor plan and defines the columnar concrete structure, departing from it at major spaces such as the two double-wide courts, the two-story lecture theater, and the library spaces with their mezzanines. At the roof, each structural bay is filled with four domed skylights between the deep V-shaped concrete beams—224 skylights across the whole building. Before looking at photos taken during our tour inside the building to see how the replacement of the skylights turned out, it is worth taking a virtual detour across the street, to the Robert B. Haas Family Arts Library at Rudolph Hall, where People Look Up at Good Architecture is on display until May 11, 2025.

Here in the exhibition, focused on the design and construction of the YCBA, we see original sketches by Kahn and lighting designer Richard Kelly, who Kahn also had worked with at the Kimbell. The angular section defined by the precast concrete beams is apparent (above), as are the louvers—Kahn disliked their appearance and called them “angry crabs”—that capped the acrylic domes. Instead of placing and angling the louvers to introduce just indirect northern light, the louvers were designed to maximize southern light. To diffuse the light entering the gallery, Kahn and Kelly installed laylight cassettes that helped to illuminate the art on the walls but detered any damage from direct sunlight. Photographs of mockups and gauging the light on the walls are included in the exhibition, illuminating (no pun intended) how much effort went into testing the effectiveness of the skylights and the various parts of their assembly.

Similarly, the YCBA and Knight Architecture worked to align the skylight replacements with the original design as well as current art conservation standards. The 224 acrylic domes were replaced with polycarbonate domes, which are more resistant to discoloration and whose shape matches the original design. Between the skylights, but out of sight to museum visitors, the flat roof, last replaced in 1998, was ripped out and replaced with a new styrene-butadiene-styrene (SBS) modified-bitumen membrane liquid roofing system.

Beneath the dome, the 832 acrylic laylight cassettes—four per skylight, at each one but those over the Lobby Court—were replaced with new ones, done in collaboration with EwingCole's Lighting Group. To cut down the amount of daylight in the galleries by approximately 30%, a tinted film on either the domes or the new laylights was considered, but in the end sandwiching an additional film-treated acrylic panel within the new cassettes was done instead. If desired, the insert can be removed to restore the daylight to its original condition.

When the YCBA reopens on March 29, it will host three exhibitions: Tracey Emin: I Loved You Until The Morning on the second floor, J. M. W. Turner: Romance and Reality on the third floor, and In a New Light: Five Centuries of British Art across the fourth floor. It goes without saying, but the last exhibition has a fitting title given its presence below the newly replaced skylights.

Given the goals of maintaining the design intent and appearance of the original skylights, there is no perceptible differences in the galleries between the 2016 and 2025 circumstances, outside of the ambient effects (sunny vs. overcast). The most dramatic differences are found in the locations of the movable partitions—the “pogos.” As seen below, these include the five perpendicular walls added to the dramatic Long Gallery, which define smaller galleries within the space and allow for considerably more paintings from the permanent collection to be hung and displayed, and the removal of walls from a gallery adjacent to the Lobby Court, which draws attention to the jarringly slender concrete columns in the middle of the space.

Two situations not related to the skylights but otherwise dealing with overhead lighting are worth pointing out. First is the reinstallation of the large cylindrical light fixtures at the top of the Lobby Court and Library Court. Difficult to maintain, the halogen fixtures were taken down roughly twenty years ago, meaning recent visitors, like myself, never experienced them in person. The originals were modified to accept LEDs, thereby requiring reduced maintenance in the future, and reinstalled, as seen in the photo at top and the close-up photo below. 

Second is the most pleasingly unexpected effect: the refraction of light through the glass blocks in the ceiling of the cylindrical stair in the Library Court. Given that the stair stops short of the roof and skylights, layers of dust had formed on the ceiling over the decades, muting the light coursing through the glass blocks. So what did not exist on a sunny day in 2016 is now—as seen on an overcast day in March 2025—a funhouse-like effect in an otherwise calm and ordered building.