"Ennead" has long referred to a group of nine Egyptian deities with names like Atum, Shu, and Tefnut. Now it also refers to a group of nine architects with names like Todd Schliemann, Susan Rodriguez, and Richard Olcott. The firm they run, founded by James Stewart Polshek in 1963 and known for years as Polshek Partnership Architects, has adopted the name—pronounced "EN-e-ad"—in the most radical identity shift since HOK Sport became Populous in March 2009.

The New York firm is known for public buildings like the Clinton Presidential Library, in Little Rock, Ark., the Standard hotel straddling Manhattan's High Line, and the Newseum, in Washington, D.C. Current projects include the Utah Museum of Natural History in Salt Lake City, the Bing Concert Hall at Stanford University, and museum renovations in New York and New Haven, Conn.

Polshek, who is 80, gave up his partnership five years ago, taking the title design counsel. The remaining partners—Schliemann, Olcott, Rodriguez, Duncan Hazard, Tomas Rossant, Timothy Hartung, Kevin McClurkan, Don Weinreich, and Joseph Fleischer—were looking to avoid the fate of Pei Cobb Freed & Partners, which people still think of as I.M. Pei's firm, 20 years after Pei retired. The partners spent a year and a half considering names before selecting Ennead Architects. They hired Michael Bierut, of the design firm Pentagram (named, incidentally, for its original five partners) to create a logo, and Lisa Strausfeld, also of Pentagram, to design the website, ennead.com.

Polshek himself, reached by phone at his apartment in Paris, said, "it was inevitable that the transition had to involve a change of name," adding that he had written a letter to 750 friends and associates endorsing the partners' decision.