The firm, which specializes in interior design, sustainable building design, branded environments and urban design, is now the anchor tenant at 215 PAS. It was operating from 16,500 square feet on the fourth floor, and took an additional 7,260 square feet on the 18th floor. The fourth-floor lease has been extended to become co-terminus with the expiration of the sixth-floor sublease space, which is being sublet from immigration attorneys Binder & Binder. A spokeswoman for building owner SL Green Realty Corp. says the firm will remain in the 18th-floor space with an option to terminate when the lease expires.

Steven Strati of Cushman & Wakefield acted on behalf of Binder & Binder in the transaction, while SL Green's Howard Tenenbaum and Gary Rosen represented both the owner and and Perkins + Will. The architectural firm has had a New York City presence since 1951.