As Cining Gong in the Forbidden City is set to be unveiled to the public, some of those behind its painstaking restoration process share their experiences. Wang Kaihao reports.
It is a closed part of the Palace Museum, also known as the Forbidden City.
But is not as quiet as one might expect.
Staff members there are busy as they rush about giving final touches to the legendary Cining Gong (Palace of Compassion and Tranquility).
This palace is set to be thrown open to the public in October to mark the museum's 90th anniversary, though a three-year major restoration was completed in 2010.
The former residence of empress dowagers will finally show its mysterious face as it is turned into an exhibition hall to display ancient sculptures.
It was used as a warehouse for decades.
Huang Yongfang, 58, a carpenter who played a major role in the project, recalls that the first step in the restoration process was to clear the weeds in front of Cining Gong.
These days he spends his time in an old workshop, which is less than 30 square meters, guiding young apprentices on how to make wooden models of dougong, a traditional Chinese construction interlocking bracket.
Huang has worked in the Forbidden City for 40 years.
"There is only one Forbidden City," Huang says emotionally recalling his work in the past decades.
"Even a slight error (in the restoration) is much more than we can bear.
"No matter how time passes, the basic skills are the same as they were hundreds of years ago. We stick to the original material, technique, style and structures during restoration."
The construction of the Forbidden City started in 1406 and finished in 1420, and most of its palaces have seen many restorations and even reconstruction through the imperial period, until the fall of the Chinese monarchy in 1911.
Unlike Western palaces, which used stone, ancient Chinese palaces used lumber as the main construction material, and the different components were joined using mortise-and-tenon joints rather than nails.
"The restoration is like placing toy bricks," Huang says. "But, you have to make sure everything is accurately placed."
When a major beam in Cining Gong was found bent and the edges of the eaves were seen to have suffered damage, the whole roof had to be disassembled to replace these things.
According to Huang, nanmu, a rare type of lumber, was widely used in building the Forbidden City during the Ming Dynasty (1368-1644), but it was gradually replaced with pinewood in the Qing Dynasty (1644-1911) due to difficulty in sourcing it.
However, even pinewood is not easily available these days. The lumber needed to restore the palace was sourced with special help from the central government.
Echoing Huang's commitment to stay true to the original in the restoration process, Bai Qiang, 59, a bricklayer who has been at the Palace Museum since 1987, says: "We stick to one thing: As long as the old materials can still be used, we won't throw them away.
"There's no need to give the palace a thoroughly new facade," he says pointing to some delicate but slightly graying paintings on the beams of Cining Gong.
"If they are basically well-preserved, we will leave them intact."
Old royal files and blueprints are major reference material for today's restorers, but a lack of old restoration logs is a problem.
So to leave better records for future restorers, Huang and Bai helped to compile logs recording this restoration of Cining Gong, the first since 1949.
Giving a glimpse of the painstaking work involved in the restoration, Huang says that the old measurement tools and pulleys are still used in the process.
"Today's industrial products are often unable to meet the need for extremely high quality in the restoration of the palace."
The palace is thus more like a handmade luxury.
For instance, the protective layers brushed on the lumber are still made from tung oil (traditional Chinese wood oil) and hemp. No chemical paint is used.
Bai says that though machine-made bricks were used to pave some of the spaces in the museum, the bricks used to restore the palace were sourced from the original workshops that produced them.
"We researched historical files to find out where bricks for the Forbidden City came from during the Qing Dynasty, and we ordered materials from them," Bai says.
The Palace Museum had earlier announced that 76 percent of its area would be open to the public by the end of 2016, which means that a lot of the painstaking restoration work will be seen by the public.
"Numerous visitors will inevitably have an impact (on the structures)," says Huang. "However, without people, what is the meaning left for a building?"
A lot of the restoration techniques used will be seen by members of the public when the museum goes ahead with plans to open branches in the northwestern outskirts of Beijing.
With the museum's expansion, there will be bigger studios to showcase the techniques which will no longer remain hidden.
But like with all traditional skills these restoration techniques could be lost if younger workers do not join the profession.
Neither Huang nor Bai's sons want to follow in their fathers' footsteps.
But there are others who think differently.
Giving his reasons for joining and staying with the profession, Zhang Fengbing, 37, who joined the group in 2001, says: "Though my salary is lower than my counterparts outside, not everyone has the privilege of restoring the palace."
There were about 400 restoration workers at the Palace Museum when work was at its peak.
Now there are less than 100, and Huang says that only about 10 young people are still actively using the ancient restoration techniques every day.
Huang also worries that newcomers to the restoration sector will not have enough opportunity to hone their skills.
It takes years to nurture a qualified restorer, and these new workers in the palace are not allowed to take part-time jobs elsewhere.
But Bai is more optimistic about the future.
"The palaces will always need mending," he says.
"No matter how small the project is, it represents the ancient Chinese construction spirit.
"As long as the young inherit that spirit, the tradition will live on."