The Su model restoration of the Zhengzong Hall of Dharma Transmission at Yong'an Temple

The Zhengzong Hall of Dharma Transmission at Yong'an Temple is located in Hunyuan County, Shanxi Province. Built in the second year of the Yuan Dynasty's Yanyou era (1315), it is an outstanding example of surviving wooden architecture from the Yuan period. As the main hall of Yong'an Temple, its architectural form, structural logic, and religious function are highly unified, reflecting the mature construction wisdom of Yuan craftsmen. The hall is five bays wide and three bays deep, employing techniques of reducing and shifting columns to significantly decrease the number of interior columns, creating a spacious, unobstructed central worship space. This facilitates the accommodation of large polychrome sculptures and allows worshippers to circumambulate, highlighting a religious spatial organization centered on the "statues." The roof is a single-eave hip-and-gable style with a gentle slope and deep eaves, showcasing the robust and steady architectural temperament typical of northern China. In terms of timber work, the outer eaves feature a five-purlin double lower angled bracket set (actually a false angled bracket), using large materials that serve both structural and decorative functions. The beam frame adopts a "che shang ming" construction method, with six purlins spanning front to back, combined with components such as forked arms, foot supports, and camel humps, forming a clear and efficient load-bearing system that ensures structural stability despite the reduced columns. Inside the hall, more than twenty Yuan Dynasty polychrome sculptures and murals depicting water and land scenes on all four walls (later heavily repainted) are preserved. The content integrates Confucianism, Buddhism, and Daoism, closely linked with the architectural interface, creating an immersive religious narrative environment. From the perspective of architectural history, the Zhengzong Hall of Dharma Transmission inherits the Song and Jin traditions since the "Yingzao Fashi" (Building Standards), while also showing a simplification trend transitioning toward the official architecture of the Ming and Qing dynasties. It is a key example for studying the evolution of Chinese wooden structural systems. Its holistic design—organic unity of structure, space, ritual, and decoration—continues to provide profound inspiration for contemporary architects.