Yingzao Fashi
In the realm of structural engineering and technical Chinese architecture, there were also government standard building codes, outlined in the early Tang book of the "Yingshan Ling" (National Building Law). Fragments of this book have survived in the "Tang Lü" (The Tang Code), while the Song dynasty architectural manual of the "Yingzao Fashi" (State Building Standards) by Li Jie (1065–1101) in 1103 is the oldest existing technical treatise on Chinese architecture that has survived in full. During the reign of Emperor Xuanzong of Tang (712–756) there were 34,850 registered craftsmen serving the state, managed by the Agency of Palace Buildings (Jingzuo Jian).