TAIYUAN, June 25 -- A guideline on the renovation of old dwellings in the ancient town of Pingyao has been released, aimed at benefiting locals while preserving the town's original features.

It has taken nearly three years for professors of architecture at Shanghai-based Tongji University and building professionals from abroad to prepare and compile the guideline, which details standards for revamping traditional courtyard houses.

The project was jointly initiated by the United Nations Educational, Scientific and Cultural Organization (UNESCO) and the county government of Pingyao in north China's Shanxi Province.

The historical town has encountered complex challenges as protection needs to go with urbanization and the improvement of living conditions of its residents, said Beatrice Kaldun, head of the culture section of the UNESCO Beijing office.

"It (the guideline) represents a commitment to safeguard and preserve the World Heritage site for future generations," she said.

Pingyao, with a history of 2,700 years, was added to the UNESCO's World Heritage List in 1997 for its urban landscape from the Ming and Qing dynasties between the 14th and 20th century.

The county has 3,797 traditional dwellings and other historical sites within its 6.4-km-long walls. But only about 400 of them are well-preserved and many are on the verge of collapsing due to a lack of adequate protection, said county chief Cao Zhisheng.

In 2012, the county government launched a renovation scheme of traditional dwellings and has completed repairing 53 houses.

Revamping the dilapidated courtyard house of resident Zhao Hongfan cost around 130,000 yuan (about 20,800 U.S. dollars), with two thirds funded by the government.

The work followed strict rules, said Zhao, who is in his 80s. "Even changing a pillar needed to be approved by the supervision team."

Shao Yong, one of the compilers of the guide, said they would issue another booklet to Pingyao residents to help increase knowledge about protection of the town.