In 2016, Chang's team began work in Xiadang township, which is in the mountains of Ningde, northeastern Fujian. President Xi Jinping served as Party secretary of Ningde in 1989, and the area is now a major draw for people interested in Party history.

During one of Xi's tours of the city's rural areas, villagers set up stands beside the road to offer officials herbal tea picked from the surrounding mountains to show their appreciation.

"When we heard that story we were moved, and we came up the idea of opening a teahouse in Xiadang to cater to visitors," Chang said.

After about 20 months, an empty property had been transformed into A Cup of Herbal Tea, which is managed by a villager. It sells beverages for about 3 yuan ($44 cents) a cup as well as snacks and Party souvenirs.

"The important thing is how these projects change the people," Chang said. "They become more involved in making their home a better place.

"Each change brings new opportunities, new transformations. The work of rural construction really has no endpoint."

Liu Yuyin contributed to this story.