Acclaimed architect Robert A.M. Stern, a prominent figure in American architecture who designed notable museums, libraries and residences — including an innovative building in downtown Allentown — died Thursday, according to a statement from the firm he founded. He was 86.

The statement did not specify a cause of death, but said Stern “died comfortably at his home.”

“At RAMSA, we grieve the loss of our founder, mentor, and friend, and remain committed to carrying forth his ideals,” the statement from the firm’s partners said.

Born in Brooklyn, New York, in 1939, Stern founded the Robert A. M. Stern Architects firm, now known as RAMSA, in 1969. He gained acclaim for his decades of work and style, which blended postmodernism with contextual design, drawing inspiration from historic and traditional styles.

He was widely known for 15 Central Park West, a luxury condominium featuring a recognizable limestone exterior in Manhattan bordering Central Park. The building opened in 2008 and has attracted prominent, wealthy and famous tenants.

Stern’s works also include the George W. Bush Presidential Center in Dallas, the Museum of the American Revolution in Philadelphia, the Gerald R. Ford School of Public Policy at the University of Michigan and Disney’s Yacht and Beach Club Resorts in Florida.

Stern’s architectural firm also designed the glass-fronted building in downtown Allentown originally known as the PPL Plaza. Construction on the $60 million structure, located on the site of the iconic Hess’s department store at Ninth and Hamilton streets, started in 2002 and was completed in 2003.

Grand Plaza on Wednesday, June 22, 2022, during DLP Capital's grand opening of the former PPL Plaza in Allentown. (April Gamiz/The Morning Call)Grand Plaza on Wednesday, June 22, 2022, during DLP Capital’s grand opening of the former PPL Plaza in Allentown. (April Gamiz/The Morning Call)

The structure was noted for its environmentally-friendly features, including a rooftop building and a glass atrium that brings natural lighting to 90 percent of the building. It was the first privately owned building in Pennsylvania to achieve LEED Gold certification for energy efficiency.

When a new owner took over the building in 2019, it hired Stern’s firm to design upgrades on the structure, which was renamed the Grand Plaza. DLP Capital bought it at an auction in 2021, and has since converted the former office building into condominiums, known as The Hamilton at Grand Plaza.

Stern served as dean of the Yale School of Architecture from 1998 to 2016. He was previously the director of Columbia University’s Temple Hoyne Buell Center for the Study of American Architecture.

The Morning Call contributed to this report.