Annabelle Selldorf, the architect behind David Zwirner Gallery’s newest space on 20th Street in Manhattan, was recently interviewed in Architectural Digest about the unique, cast-in-place concrete façade of the building, the challenges created by such a demanding design, and her experience working with Zwirner to conceptualize the design of the building.  ”Truthfully, it was David who wanted the building to be cast-in-place concrete.”  She says. “But like any layperson, he didn’t necessarily know what that entailed. He just knew that he wanted a certain look and feel. And I, knowing more about what it takes to actually do a concrete structure, realized this posed a formidable challenge.”