The demolition of a rock-covered rooftop villa atop a 26-story Beijing apartment block has been completed, leaving a mountain of construction waste to haul off.

The villa was taken down more than four months after Beijing Haidian district's chengguan, or urban management authorities, ruled that it was an illegal building and ordered the owner, Zhang Biqing, to dismantle it within 15 days.

The villa was built of rocks and decorated with trees and bushes. It covered about 800 square meters, according to a statement provided by the chengguan on Friday.

Zhang owned an apartment on the 26th floor as well as another stand-alone apartment located overhead, at the center of the building's roof. That one became the villa.

Earlier, an apparent delay raised speculation that Zhang might have slowed the process deliberately, hoping to keep part of the building once public attention subsided.

But Zhu Wei, a chengguan official, said that the demolition didn't slow down and that the owner had cooperated with officers.

While the main part of the villa has been dismantled, the removal of the waste will continue into 2014 because of lack of disposal facilities and because of weather, the authority said.

The authority also said it will send monitors to check on progress, and that it will ask for help from the local property-management company to speed up the removal.

Zhang, the owner, told China Daily that he was not currently in Beijing and had not followed the demolition process.

"I employed the company that built the garden - the villa - to dismantle it and they haven't told me the process yet, but I have heard that they have finished their work," Zhang said.

"I feel distressed. You should have seen the pictures they took, how beautiful it was. I spent great effort on it - almost six years. I dare not ask about the process of demolition."

Zhang said he fell ill and is still in poor health after his "garden" was exposed in the media. He said he often has nightmares.

"My family members prevent me from reading news and don't even allow me to watch TV," he said. "I am not coming back to Beijing in the near future because I am worried that I couldn't bear to see that my garden is gone."

Hu Zhenhua, director of the Institute of Urban Management Science in Shenzhen, said the cost for owners of illegal buildings is still quite low, which is why there are so many such structures in China despite long-standing prohibitions.

Under current rules, the authorities will order the owners to remove the structures but will not hand out additional punishments, Hu said, adding that some adjustments need to be made to the regulations.

"Those people usually build illegally out of economic interest. We should raise the cost for them. Otherwise, the problem cannot be solved," Hu said.

Illegal rooftop buildings have been found this year in other cities in China after Zhang's villa was exposed. Twelve illegal rooftop buildings ranging from 180 to 240 sq m were reported in Guiyang, capital of Guangzhou province. The owners reached agreement with local authorities on Aug 23 to dismantle them.

Demolition began on Oct 30, but it isn't known whether that process has been completed.

A two-story villa with a swimming pool and gym on the roof of a 26-story building in a downtown residential community made headlines in Xi'an, capital of Shanxi province, in early August after a neighbor posted photos online. Local authorities ordered its removal on Aug 21 and work began two days later.

On Aug 20, a temple-shaped villa atop an apartment building in Shenzhen, Guangdong province, received media attention. The local law enforcement department said on Sept 5 that it would be removed within one week.

houliqiang@chinadaily.com.cn