Steven Izenour; Architect, Author

Steven Izenour, a partner in Venturi Scott Brown, the iconoclastic Philadelphia architecture firm known for its celebration of commonplace American buildings, died of a heart attack while on vacation in Vermont. He was 61.

Izenour, who joined the firm in 1969, was a co-author, with Robert Venturi and Denise Scott Brown, of “Learning From Las Vegas,” one of the seminal books on architecture in the 20th century.

The provocative 1972 book called on architects to be open-minded about the tastes and values of ordinary people and what the authors plainly referred to as “ugly and ordinary” architecture.

Izenour taught extensively and was particularly known for his knowledge of everyday signs and symbols in American towns and cities, from billboards and neon signs to fast-food logos.

“For the last 30 years, my partners and I have made a hobby of learning from places everyone else ignores,” Izenour told The Times recently. “You want to look at these places not just in some esoteric design context, but put it in a larger social and economic one. We’re not just architects but historians and sociologists.”

He found much to admire in places like Vegas, home of the garish and the outsized, and Miami’s Art Deco South Beach. Over the last few years he worked on a plan for the restoration of Wildwood, N.J., a beach town known for its dense concentration of 1950s and 1960s “Doo-Wop style” commercial architecture.

He played a leading role in designing several exhibitions, including a show at the Renwick Gallery in Washington in 1976 called “Signs of Life: Symbols in the American City,” which celebrated all-American, everyday sights. One gallery was devoted to the Las Vegas Strip and featured a giant McDonald’s arch for a gateway.

“We say that too much design control creates a rather sterile environment,” Izenour said in explaining the show. “We’re telling other professionals how you can learn from things you hate.”

Born in New Haven, Conn., he earned his undergraduate degree at Swarthmore College and an architectural degree from the University of Pennsylvania, where he studied under Venturi and Scott Brown.

He won many awards for his designs, including an American Institute of Architects Honor Award for his parents’ house on Long Island Sound. He worked with his father, the noted theater designer George S. Izenour, to light the Benjamin Franklin Bridge in Philadelphia for a celebration of the Constitution’s bicentennial. He also was the primary designer for a popular children’s treehouse at the Philadelphia Zoo that was designed like an ecosystem and featured interactive elements.

“He was a great part of the messy vitality here,” said Daniel McCoubrey, a senior associate architect at Venturi Scott Brown. “One of his great abilities was to see as a child sees. He always had that wonderment and ability to see through preconceptions about things.”

Izenour is survived by his wife, Elisabeth; two daughters, Ann Kristine Stephany and Tessa Izenour; a son, John Hilt; and his parents, George and Hildegard.