San Francisco’s Lakeshore Plaza shopping center is home to more than a dozen national chains, from Wells Fargo to Chipotle to Petco.

So it might seem like a simple matter for Peet’s Coffee and Tea to expand its existing shop in the retail center at 1509 Sloat Blvd. into an adjacent space previously occupied by a poke bowl restaurant.

But the approval process for the expansion took more than eight months. And Peet’s still needs to acquire building permits, which usually take another few months.

Peet’s has run into these hurdles because it’s a chain store. In San Francisco retail districts outside of downtown, any retailer with 11 or more locations worldwide typically needs a special type of approval to open — or even expand into an adjacent empty space.

The permits, called conditional use authorizations, greatly extend the time it takes to open a store. Eight months to open is far longer than in other major cities like New York, according to real estate brokers. San Francisco officials have acknowledged that such lengthy processes may be contributing to the wave of vacant storefronts blighting many neighborhoods and deadening streets.

“Eight months is the standard” in San Francisco, said David Glassman, a senior project manager at Glassman Planning Associates, Peet’s consultant in navigating the approvals. “This is why my job exists.”

During the review process, chain stores must notify neighbors of their plans. Opponents can request further city reviews. A hearing at the Planning Commission can take months to schedule.

Even some supporters of chain store restrictions think the current process is too drawn out. Combined with high construction costs, the process leaves spaces empty even when there’s an interested tenant, merchants say.

“The neighborhood should have some power,” said Tim Yip, who lives near the Lakeshore Peet’s. An eight-month wait, he said, was “way too long.”

Yip works at North Beach’s Coit Liquor store, which got help from Supervisor Aaron Peskin’s office to find a temporary space after two fires forced it to relocate in 2018. Yip said faster approvals are needed for both chains and smaller stores.

“I hear horror stories,” he said. “There’s too many vacancies.”

A city study released in March found that 224 conditional use authorizations between January 2015 and March 2018 took an average of 270 days, or about nine months, to complete. The approvals are also required when spaces change into other types of businesses, such as a retail shop becoming a restaurant. Only four were disapproved, 45 were withdrawn, and 62 were still open at the time of the study.

Phil Jacobson, who visits the Lakeshore Peet’s every day, said he supported fewer restrictions on chain stores.

“Less regulation is good for business, for anybody,” he said while sitting outside the shop last month.

Voters approved the chain store approval requirements in a 2006 ballot measure, Proposition G, in a bid to protect mom-and-pop shops. Downtown doesn’t have the restrictions, while three neighborhoods — North Beach, Chinatown and Hayes Valley — ban chain stores completely.

Advocates of chain store restrictions say they help protect small operators and keep rents down.

Some Southern California cities also have moved to restrict chain stores in some areas, but policies are less sweeping than San Francisco regulations. Santa Monica has looked at banning fast-food chains in its Third Street Promenade area. Malibu restricted chain stores in a 2014 ballot measure, but that ban was overturned after a developer sued.

Cosimo Pizzulli, president of Beverly Hills architecture firm Pizzulli Associates, said local building permits can take three to five months to obtain, and cities can be picky over architectural designs and materials.

In contrast, New York has no chain store restrictions, and permits can be obtained in weeks.

The Planning Commission approved the Peet’s expansion last month, despite some neighbors calling for a delay because they felt they weren’t properly notified of the expansion.

“Peet’s in and of itself is not an issue, but the notice is. Notices were not received by the homeowners who live on the perimeter of the plaza, nor was it received by our organization,” Bill Chionsini of the Lakeshore Acres Improvement Club, which represents nearby homeowners, said at a July meeting. He also objected to Peet’s holding a community meeting downtown during working hours, instead of at the shopping center.

Peet’s will expand into a space formerly leased by another chain, Ahipoki, a poke bowl shop that closed earlier this year. Ahipoki also required a conditional use authorization to open, according to city records.

“We’re not displacing another mom-and-pop store,” said Glassman.

Peet’s didn’t respond to a request for comment. The coffee shop will double from 900 square feet to 1,800 square feet, and increase seating from 11 to 39, said Jason Dedmore, Peet’s director of real estate, at the July planning hearing.

Other chains that have navigated the city’s approval process include Safeway, which recently gained approval to open an Andronico’s grocery store in the Outer Richmond after months of review. But the city rejected a Whole Foods proposal to open in a long-vacant space on Polk Street.

An effort by then-Mayor Ed Lee to loosen chain store restrictions led to minor changes in 2014. Mayor London Breed is now focusing on expediting the retail permitting process, but she hasn’t sought any changes in the chain store policy.

Roland Li is a Chronicle staff writer. Email: roland.li@sfchronicle.com Twitter: @rolandlisf