Adithya Sambamurthy/The Bay Citizen

Pedestrians near the San Francisco Chronicle Building on Tuesday, April 5, 2011

The developer will have to submit the review to the San Francisco Planning Commission before making changes to the property. Chase said that because the Historic Preservation Commission is part of the planning commission, he intends to recuse himself from any decisions.

In recent weeks, city officials said Hearst and Forest City executives had brought a “road show” to City Hall to meet with officials, even though the project appears to be years from requiring city approval.

“Their ideas are innovative and very responsive to market needs,” said Jennifer E. Matz, the current director of the mayor’s Office of Economic and Workforce Development. “I’m really interested in seeing how their plans develop.”

Whatever happens, it is clear the Chronicle building and its surrounding neighborhood are already changing dramatically.

On a recent afternoon, a young woman in a bright teal skirt walked gingerly across the Hub, a shared work space for startups on the first floor of the Chronicle building, holding a cup of coffee while reading from a MacBook Air that was perched precariously on her forearm.

“I sometimes look out the window; there are all these interesting-looking people down there, and I don’t know what they’re doing,” said Carl Nolte, a veteran editor and columnist who has been at the Chronicle since 1959. “But they bring vitality to the place. I like that.”

In 1924, the Chronicle moved into its building South of Market — South of the Slot, as the working-class neighborhood’s Irish residents called it. The paper settled in alongside food-processing businesses, maritime supply shops and warehouses.

Twenty years ago, the financial district began to spread south of Market, and “full-court redevelopment” began to creep southwest along Mission and Howard Streets, said Fracchia.

Adithya Sambamurthy/The Bay Citizen

Jon Abaitua, right, and Jose Mari Auzarraza work at the Hub on the first floor of the Chronicle building. The Chronicle's newspaper staff is clustered on the third floor.

The Chronicle operations once occupied most of the building. But in 2009, after laying off half its editorial staff, the newspaper consolidated its editorial operations on the third floor.

Since the first dot-com boom 10 years ago, newspaper staff members say, rumors of an imminent move have circulated as regularly as wacky news tips about the Zodiac killer. Some speculated that the paper could be relocated as far away as Marin County. In a 2007 interview, Stephen T. Hearst, the general manager of Hearst’s Western properties division, publicly mulled razing the Chronicle building.

Brad Paul, a housing consultant hired by Forest City to work on the project, said the developer is now operating under the assumption that the Chronicle building will be left intact. But Arena, who is directing the project, was more circumspect, saying that at a minimum, Forest City intends to “celebrate” the building’s historic elements, like the clock tower. She emphasized that Forest City would begin a lengthy process to solicit community input and that no firm plans had been drafted.

The city openly views the project as part of its changing landscape. The Chronicle, said Ken Rich, a project manager in the mayor’s Office of Economic and Workforce Development, would be ideal for the large-scale expansion of nimble, entrepreneurial-minded companies like the ones that are now proliferating in the building.

“The interesting thing about this project is it makes people ask the question of, ‘Where are jobs going to go in the next two decades?’” said Rich.

Gabriel Metcalf, executive director of San Francisco Planning + Urban Research Association, a local policy group, said the neighborhood around Fifth and Mission is a logical extension of the city’s continuing economic evolution. “The location is extraordinary,” Metcalf said. “It’s important to the city that we really make use of this site because they are trying to invent a new kind of work environment that is going to work for the economy of the future.”

This article also appears in the Bay Area edition of The New York Times.