Hong Kong (CNN) -- The plan to raise what would be the world's tallest building in a dizzyingly fast time is in danger of not getting off the ground at all.
According to reports in Chinese state media, Broad Group, the developers for Sky City, have so far failed to get the proper permits required to proceed with construction. The company put the first spade in the ground in the 202-story project to much fanfare on July 20.
Developers hope it could be built within the year.
The 838-meter construction in Changsha, the capital of China's central Hunan province, would rise ten meters higher than the world's current tallest building, the Burj Khalifa in Dubai.
"Broad is still currently in the beginning stages of arranging the construction project," a Changsha Urban Planning Department representative told CNN.
"So far, they've undergone the process to obtain 136 mu [22 acres] of land, but that's it. They're still in the very basic beginning stages. We've been giving a lot of attention to this case, and everything they've done has been according to law."
For its part Broad Group insisted everything was above board. "We have not yet started work on Changsha's Sky City," a Broad Group press officer told CNN. He added that they have evidence to show no laws have been broken.
Penalties for illegal construction vary widely across China between the countryside and cities, as well as between residential and commercial use.
In Chengdu, the capital of Sichuan province, baseline fines for illegal construction range from 5% to 10% with investigative fees as much as doubling the amount. Additional penalties for various infractions can then double the original fine, according to one official government website.
In the southwest megacity of Chongqing, the fine for the illegal construction of a commercial building is 50% of the cost of construction, according to another government site.
If similar penalties exist in Changsha as for Chongqing, Broad Group could be fined nearly $750 million. Sky City's total construction cost is $1.46 billion.
Construction advocates have touted Sky City's green credentials: It will save on energy and land use, creating an all-in-one home, office, shopping, farming and recreation environment for some 30,000 residents that no one ever needs to leave.
Critics -- including architectural experts and the Chinese public -- worry about safety because of the use of non-traditional building techniques and the pace of construction. Broad Group pioneered the use of pre-fabricated steel-and-concrete blocks -- akin to Lego blocks -- that can be quickly hoisted into place. While the Burj Khalifa took five years to build, Broad Group says this "fast-building technology" means it can construct Sky City in just ten months.
Sky City will be completed in April 2014, said Broad Group in earlier statements.
However when questioned by CNN, the company's press officer hesitated to provide a start date for construction. He added that plans will be announced at an as-yet unscheduled future press conference, leaving construction plans for Sky City firmly frozen on the ground.