Outdoor tables saved thousands of New York City restaurants from ruin when they were forced to close their dining rooms during the COVID-19 pandemic.

But four years into an experiment that transformed New York’s streetscape — briefly giving it a sidewalk cafe scene as vibrant as Paris or Buenos Aires — the freewheeling era of outdoor dining has come to an end.

Over the weekend, restaurants hit a deadline to choose between abiding by a strict set of regulations for their alfresco setups or dismantling them entirely — and thousands chose to tear down the plywood dining structures that sprouted on roadways in the pandemic’s early days.

Fewer than 3,000 restaurants have applied for roadway or sidewalk seats under the new system, a fraction of the 13,000 establishments that participated in the temporary Open Restaurants program since 2020, according to city data.

Mayor Eric Adams said the new guidelines address complaints that the sheds had become magnets for rats and disorder, while creating a straightforward application process that will expand access to permanent outdoor dining.

But many restaurant owners say the rules will have the opposite effect, dooming a vestige of the pandemic that gave them unusual freedom to turn parking spaces into rent-free extensions of their dining rooms with minimal red-tape.

“They’ve found a middle ground to do one thing while saying another thing,” said Patrick Cournot, the co-founder of Ruffian, a Manhattan wine bar. “They’ve managed us out, essentially.”

Ramshackle plywood dining structures seemed to sprout from New York City’s streets almost overnight in the early days of the COVID pandemic.

With its crowded sidewalks and traffic-choked streets, the city had never really been known previously for an outdoor dining scene. But with customers banned from congregating indoors for months, the city gave restaurants a green light to expand dining areas onto public sidewalks and roadways.

Simple sheds for outdoor seating were soon replaced or expanded into more elaborate constructions, which have remained standing long after the days of social distancing and disinfected groceries. Restaurants added planters, twinkling lights, flowers and heating lamps so people could dine outdoors well into the cold weather. Other outside dining spaces appeared inside heated igloos, or with open fire places and under tiered rooftops.

Now, these structures must conform to uniform design standards, with licensing and square footage fees that could total thousands of dollars a year, depending on size and location.

But the most significant change, according to many restaurants, is a requirement that the roadside sheds be taken down between December and April each year.

That’s a deal-breaker for Blend, a Latin Fusion restaurant in Queens that once won an Alfresco Award for its “exemplary” outdoor set-up.

“I understand they want to keep it consistent and whatever else, but it’s just too much work to have to take it down every winter,” said manager Nicholas Hyde. “We’re not architects. We’re restaurant managers.”

Blend’s 60 outdoor seats “kept us alive” during the pandemic and remained well-used with diners who “since COVID just want to be able to enjoy themselves outside,” Hyde said. But after looking over the application, they decided to remove the curbside structure, opting instead to apply for sidewalk seating that can remain year-round.

Of the 2,592 restaurants that have applied for the new program, roughly half will forgo roadway set-ups in favor of sidewalk-only seating, according to the city.

Karen Jackson, a teacher, was going to lunch indoors Tuesday at Gee Whiz diner in Tribeca, one of the restaurants that took its outdoor shed down ahead of the deadline.

Jackson said she has mixed feelings, recalling how having coffee outside in a shed was one of the few entertainment options available early in the pandemic.

“Some of them were really cute,” but others were unattractive and rat-infested, Jackson said.

“Unfortunately I think the places with more money were able to build the cute sheds and the places that were struggling couldn’t,” she said.

Andrew Riggie, the executive director of the NYC Hospitality Alliance, said the city should examine why so few eligible restaurants have applied, and consider how costly it will be to take down, store and rebuild the structures each year.

Applications for roadway dining structures must also undergo a review from local community boards, where some of the fiercest debates over outdoor dining have played out. Opponents have complained that the sheds eliminate parking, contribute to excessive noise and attract vermin.

On the Lower East Side, a row of sheds owned by a sushi counter, a coffee shop, a Mexican eatery and a Filipino restaurant stand side-by-side.

Paola Martinez, a manager at Barrio Chino, the Mexican restaurant, acknowledged the trash headaches and neighborhood conflict — on one particularly busy night, an angry neighbor hurled glass at the structure from an upstairs window, she said. But her restaurant has applied to stay in the roadway.

“It attracts a lot more people to the area,” she said. “It’s been great for business.”

City officials say restaurants who missed the deadline are welcome to apply in the future, while those that haven’t will soon be fined $1,000 each day their set-ups remain.

Watching contractors take a crowbar to his once-vibrant dining shed, Cournot described a sense of relief. He said the sheds had come to symbolize an incredibly challenging period when a coworker died from the virus and a drop in sales nearly ended his East Village wine bar.

“When people say it’s the end of an era, I think it’s the end of a uniquely awful era for restaurants in New York,” Cournet said. “Like going through any kind of extended group trauma, the positives that we feel collectively are a little bit of a mirage.”