The program requires visitors “to focus on the details and garments themselves,” says OMA New York director Shohei Shigematsu. “In order to do that, we had to create a neutral environment, so that the clothing stands out.”

Led by Shigematsu, the design team devised a scaffolding system, tautly veiled by scrim textile, in the given space—a run of narrow galleries on each of the two floors, octagonal in plan, with a skylit atrium on the upper level. At its heart, they built a rotunda (43 feet in diameter and 52 feet high), topping it with a shielded truss dome that blocks the sun from the existing skylight. Two series of arcades—one surrounding the rotunda, the other below the first—feature displays organized by specific skills of fine dressmaking, such as pleating, embroidery, lacework, and so on.

Dubbed “Ghost Cathedral” by the architects, the ephemeral structure-within-a-structure is revealed or concealed, like a stage set, depending on how it is lit. “So while you’re circulating, you can always see another space,” Shigematsu notes. “It is never claustrophobic.” Nor is it overwhelming. The architects’ sparing use of electronic media is limited to 3-D-mapped projections that magnify exquisite details of dresses in the rotunda and its adjacent niches—most notably a close-up in the dome of a golden pixilated pattern, hand-painted and embroidered, on the train of a Chanel wedding gown by Karl Lagerfeld.

Shigematsu wanted the experience to be unexpected, he says, “to focus on the pristine details and to treat them like art.”