Renzo Piano, on the other hand, has designed 25 major museum projects — 21 will have been completed as of next month, with four more still under way. Since 1995, the Renzo Piano Building Workshop has averaged one new museum building every year, a pace that shows no signs of slowing.

A record appears to be in the making. “I can’t think of anyone who comes close,” said Martin Filler, the architecture critic for The New York Review of Books.

Mr. Piano, 76, is among the world’s handful of elite “starchitects,” and he won the field’s highest honor, the Pritzker Prize, in 1998. His firm has offices in New York and Paris as well as in his native Genoa, Italy.

By no means does he limit his attention to museums. In his 50-year career, Mr. Piano has designed Europe’s tallest building, the Shard in London; an airport terminal; concert halls; The New York Times Building; and the occasional house.

But museums may be his most lasting legacy. “This has been the Renzo Piano era,” said Eric M. Lee, the director of the Kimbell Art Museum in Fort Worth, the site of Mr. Piano’s latest museum project. The $135 million addition opens Nov. 27.

When handed a list of all of his museum projects, even the architect himself was taken aback. “It is amazing,” said Mr. Piano, seated in his Greenwich Village office, across the street from the site where his design for the new Whitney Museum of American Art isunder construction.

“Looking back, I counted, and I said, ‘Is this true?’ ”

It was a museum that vaulted Mr. Piano into the big leagues. His design for the Centre Georges Pompidou in Paris, which opened in 1977, was done in collaboration with the British architect Richard Rogers. It instantly became both recognizable and influential, helping usher in the era of “museums as entertainment destinations,” as Mr. Filler put it.

Mr. Piano said that he did not consider himself a museum architect per se but that public buildings of any kind galvanized him.

“I love to make civic buildings,” he said. “I love making a jewel like the Kimbell; it will change life for people for the next few centuries. An office building may come down in 50 years, but this is forever.”

Atlanta, Boston, Chicago, Los Angeles, Amsterdam and Basel are among the cities with museum buildings by Mr. Piano, many of them additions to existing structures or campuses. He has done so many of them that his work has become a reference point in the field.

Adam D. Weinberg, the director of the Whitney, said his museum’s search committee had interviewed 10 architects for the job of building a new home for the museum in the West Village. Mr. Piano was not among them.

“We asked them all to name their favorite museum building, and nine of them mentioned one of Renzo’s, usually the Menil,” Mr. Weinberg said, referring to the 1987 Menil Collection in Houston, one of Mr. Piano’s signature designs.

“Our committee said, ‘If he’s the best museum architect, why don’t we talk to Renzo?’ ” Mr. Weinberg recalled. They did, and his building is scheduled for completion in 2015.

“The No. 1 reason he gets these commissions is that he’s the best on putting the art first,” Mr. Weinberg said. “He has a great sense of scale, a great sense of proportion.”

Mr. Piano’s sophisticated and art-friendly louver systems for roofs are a frequently cited attribute. “His hallmark is magically filtered light,” Mr. Filler said.

Those qualities add up to an irresistible combination for selection committees. Mr. Piano confirmed that he had turned down dozens of other museums that wanted new buildings, just because of his workload.

“He’s been the go-to guy for institutions who want to make sure they make a safe and timeless choice,” Mr. Filler said.

Mr. Piano has drawn wide praise for many of his buildings, in particular his smaller museums like the Menil, though more than one critic has cited “fatigue” at the ubiquity of his work.

Nicolai Ouroussoff wrote in The New York Times that “the art takes center stage” in Mr. Piano’s 2009 addition to the Art Institute of Chicago, in galleries that are “beautifully proportioned,” while Mr. Filler said he thought the same project “falls into the category of museum as airport terminal.”

Asked whether he was in danger of repeating himself with gestures like his modern arcades composed of highly articulated steel mullions, Mr. Piano scoffed.

“There’s nothing so different as one museum from another,” he said of the disparate collections and mandates of each project. “You must be pretty stupid to repeat yourself. I use the same language to tell a different story.”

Mr. Piano cited the specially created concrete of the Kimbell’s interior walls as a distinctive new feature, as he has never before used that material as a backdrop for art.

The Kimbell project is also notable because it brings Mr. Piano’s practice back to its roots. In the late 1960s, he worked for Louis Kahn, the architect of the 1972 original Kimbell building, considered a classic of modern architecture.

Not only that, when Mr. Piano was in talks with the art patron Dominique de Menil in the 1980s about the design of the Menil Collection, “The first thing we did was to go look at the Kahn building at the Kimbell,” he said, adding that he took inspiration from its “humble attitude.”

“It closes the circle,” Mr. Piano said of the commission.

Mr. Piano said that his good working relationship with the descendants of the Kimbell’s founders also helped persuade him to take the project.

“Good clients are essential, and that doesn’t mean someone who always said yes,” he said, adding that he thought his own success in the past was directly tied to the quality of the clients. “Sometimes they are good, sometimes less good.”

The biggest critic of his museum work, it turns out, may be Mr. Piano himself.

“One thing is for sure: I’m never happy,” he said. “There’s always something missing in a job. The day you are happy, you stop.”

> via NYTimes