CHANGSHA, China » China is slowing down, but the buildings keep going up — until now.

China is home to 60 of the world’s 100 tallest buildings now under construction. But the skyward aspirations of Changsha, the capital of Hunan province, have inspired incredulity tinged with hostility.

Broad Group, a manufacturer based in Changsha, has been planning to erect the world’s tallest building here this winter, and in record time. The 202-story "Sky City" is supposed to be assembled in only four months from factory-built modules of steel and concrete early next year on the city’s outskirts. The digging of foundations began on July 20.

But the project’s scale and speed have set off a burst of national introspection in recent days about whether Chinese municipal leaders and developers have gone too far in their increasingly manic reach for the skies.

"The vanity of some local government officials has determined the skylines of cities," an editorial in the People’s Daily newspaper, the Communist Party’s mouthpiece, said on Aug. 12.

On Tuesday, the tycoon behind the project said in a telephone interview that he had ordered a pause in work at the site while waiting for further approvals from regulators in Beijing.

"It’s because of all the concern in the media and on the Internet, the government is a little wary and has slowed down the process," said Zhang Yue, the chairman of the Broad Group.

But he vowed to finish the building, saying that he expected a delay of no more than two to three months, with completion in June or July next year instead of the original plan of finishing it in April. Workers have already dug a large hole in the ground for the foundations and have just laid a four-lane road to the site to bring in large earth-moving equipment.

"No matter how high the obstacles, I will for certain overcome them to make sure this project is completed," Zhang said. He declined to identify who in Beijing had delayed his project, but said that he had not been asked to make any tweaks to the design.

David Scott, a prominent structural engineer in London who has worked on many extremely tall buildings, said that regulatory delays were a periodic problem for such projects all over the world, but could usually be overcome.

Local officials say that while they have transferred the land for Sky City to Broad Group and have been installing electricity and water lines for the project, final approval for the project is still "in progress" from building safety experts in Beijing.

The blueprints for Sky City call for a stack of long, skinny rectangles that taper to a narrow top, like a very tall and angular wedding cake. It bears a blocky resemblance to the 110-story Willis Tower in Chicago, formerly the Sears Tower, which was the world’s tallest building until 1998 but is now being left in the shade by numerous rivals.

Beijing, Shanghai, Shenzhen, Guangzhou and Chongqing, each similar in population to metropolitan New York, are now finishing one building apiece that will top the Willis Tower. Wuhan, the size of greater Houston, is erecting two buildings taller than the Willis Tower and Tianjin, the size of metropolitan Chicago, is constructing three, according to the Council on Tall Buildings and Urban Habitat, the Chicago nonprofit that tracks skyscraper bragging rights.

Ambitious local officials, together with state-owned companies and state-owned banks, stand behind most of these projects, raising fears that taxpayers may eventually pick up the bill if projects prove uneconomical.

"If you let the market decide, I don’t think a lot of these tall buildings would proceed," said Chau Kwong Wing, a professor of real estate and construction at Hong Kong University. Despite public concerns, there is no sign so far that any of the many very tall buildings under construction in China has been blocked by regulators in Beijing, he and Zhang both noted.

Sky City is the most ambitious project of all, and so it has become the lightning rod for criticism of the trend. Chinese media have been openly skeptical about the project, questioning its safety, construction speed and the wisdom of relying on prefabricated modules.

But work nonetheless continued earlier this month at the site. Bulldozers sliced slabs of earth and six drilling rigs bored holes for a drainage system.

Zhang said in an interview at his headquarters that he had all the approvals needed to start work, and he and other executives said that it was common in China to keep working pending further approvals.

If built as planned, the building would be only 10 meters, or 33 feet, taller than the 2,722-foot Burj Khalifa in Dubai, the world’s tallest building since 2010. Sky City would cram 39 more floors into its height than the Burj Khalifa, partly because Sky City would be mostly apartments, which do not need the same hollow spaces under the floors as offices require for wiring and cooling, and partly because the ventilation shafts, electrical wiring and even indoor floor tiles will be packed into the modules while they are still at the factory.

The bottom 15 floors would include offices, a school with kindergarten through eighth grade and clinics. A schematic from Broad Group shows a hotel near the top and a restaurant and coffee shop at the apex.

The emphasis on apartments reflects the reviving real estate boom in China — some in China and abroad call it a bubble — as the government has told state-owned banks to lend more in recent months, in response to signs of weaker economic growth.

Zhang insisted that the local government in Changsha is not bankrolling his project. But he said for the first time in the interview at his headquarters on Aug. 7 that while Broad Group remains the official owner of the building, he has negotiated deals in recent months for the sale of practically the entire building to "four or five" investment companies. He said then that not all of these deals have been completed; on Tuesday, he declined to comment on whether the delay would affect his financing.

He declined to identify the buyers except to say that they were in the private sector, not part of the government and were spending their own money instead of relying on bank loans. That would be an extremely unusual combination in China, where most large real estate developments depend on low-rate loans that politically connected companies and individuals obtain from state-owned banks.

Zhang made his first fortune selling energy-efficient central air conditioning systems. He then moved into construction four years ago, setting up what are now six factories here. Each factory is the length of five football fields laid end to end, and manufactures 13-foot-by-51-foot modules for the assembly of high-rises. Zhang is trying to sell franchises for building module factories to construction companies and steel mills around the world.

Zhang exudes confidence that Sky City tower will be built soon, even at the risk of immodesty. "Things that I envision are definitely going to get done, no doubt," he said in an interview at his headquarters. "Ordinary people do not know the challenges and issues I face every single day. There are so many issues, 24 hours in a day are not enough for me to deal with all of them."

People’s Daily was more glum, noting that the Empire State Building, completed in 1931, took about two decades to fill and become a commercial success – and was initially nicknamed the "Empty State Building."

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