Why do Jiangnan folk houses still retain the architectural customs of ancient buildings?

Jiangnan folk houses are the embodiment and carrier of Jiangsu, Zhejiang and Shanghai traditional culture. The eastern part of the Yangtze River Delta has been a land of plenty since ancient times, with developed traditional culture, developed economy and strong social and humanistic atmosphere. Historically, it is famous for its talented people in the south of the Yangtze River. Compared with other regions, it has been in a long period of peace, with few wars, few local residents and few foreign cultures, so it has always been able to preserve the local culture.