Yingzao Fashi: Shared Rules for Dimensions, Materials, and Craftsmen

In 1103, the Northern Song government published the Yingzao Fashi, compiled and revised by Li Jie. Official building regulations had existed before this, and Li Jie was ordered to revise them, completing his manuscript around 1100. Publication must therefore be distinguished from the initial compilation and completion of the revision. The Directorate of Buildings, responsible for palaces and other government projects, needed more than instructions telling craftsmen how to work: it also needed methods for estimating labor time, issuing materials, and auditing expenditure.

Government construction in the capital, Dongjing, or Kaifeng, was large in scale and involved many trades. If the terminology for work, component dimensions, and methods of calculating materials varied from one party to another, officials found it difficult to check actual requirements, leaving scope for inflated claims and waste. Li Jie organized craftsmen’s experience and earlier texts into provisions that could serve as shared references, providing a more stable connection between work on site and government accounting.

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The book organizes its contents into explanations of terminology, regulations for different trades, labor standards, material allowances, and illustrations. Stonework, major carpentry, minor carpentry, tiling, and decorative painting each have their own subjects. Load-bearing frames, doors and windows, roofing materials, and decorative techniques are not treated as one undifferentiated construction activity. Definitions helped administrators identify components, regulations explained how to make them, and labor and material provisions translated those methods into requirements for workers and supplies.

Li Jie did not independently invent every mortise-and-tenon joint and bracket set. Many methods recorded in the book came from long-established craft traditions; compilation involved investigation, selection, naming, and standardization. Jiren Feng’s research further shows how images of flowers, trees, branches, and leaves in component names were connected with Song culture. Technical terms distinguished shapes and functions while preserving the ways craftsmen and scholars understood buildings.

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Major carpentry used the cai as the basis for organizing dimensions. Cai were divided into eight grades, selected according to conditions such as a building’s scale. In each grade, the broader cross-sectional dimension was divided into fifteen fen and the thickness into ten, maintaining a ratio of three to two. Here, fen was a relative measure that changed with the cai grade, not a fixed length identical in every case. For example, first-grade cai measured nine cun across and six cun thick, while sixth-grade cai measured six cun across and four cun thick. The same number of fen therefore produced different actual dimensions.

Craftsmen could first choose a cai grade and then derive the dimensions of related components from the rules, reducing the need to estimate each part from scratch. Additional concepts such as qi (栔) and zucai (足材) enabled different components to be coordinated within the same proportional system. It provided scope for variation governed by rules, but did not mean that an entire building was simply an enlargement of one drawing, or that every privately built structure strictly followed it.

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The book’s puzuo bracket assemblies involve the layering and projection of components such as dou blocks, gong bracket arms, and ang lever arms, connecting column tops, the beam framework, and projecting eaves. Understanding a bracket set requires knowing how its components join, where they are placed, and how adjacent sets and the structure above work together. Treating bracket sets as carved ornament on appearance alone makes it impossible to understand why the book repeatedly specifies their dimensions, levels, and combinations.

Illustrations help readers connect written provisions with physical forms, but the images still require interpretation through terminology and construction experience. Some details are described briefly because contemporary craftsmen may already have regarded them as common knowledge. Modern readers, lacking that background, need measured surveys of surviving buildings, observation of components, and comparison of different textual versions to reconstruct the original working relationships more accurately.

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Planning a project required more than knowing the length of a timber: it also meant estimating the labor and supplementary materials needed to turn it into a component ready for installation. Labor standards connected different processing tasks with the workforce required, while material allowances provided corresponding bases for quantities. Calculations were to vary with complexity and the object being worked on. Separate rules for carpentry, stonework, painting, and other trades avoided applying one crude standard to every project.

This enabled project administrators to prepare budgets from component numbers and construction methods, and to compare actual claims against the regulations. The rules had the administrative purposes of curbing inflated claims and establishing common standards, but written provisions could not guarantee complete compliance on every project. Raw-material quality, transport conditions, season, and craftsmen’s skill still affected costs on site. Studies of official manuals must distinguish the order they sought to establish from the actual operation of particular building sites.

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After its Song publication, the Yingzao Fashi underwent reprinting, copying, and editorial work; the versions behind the texts and illustrations read today must therefore be identified. In the twentieth century, Liang Sicheng and others combined textual study with measured surveys of historic buildings to explain long-obscure terms, dimensions, and structural relationships, making this official manual a major source for Chinese architectural history. Modern annotations must also be distinguished from the original: later explanatory diagrams cannot be treated as drawings left by Song building sites.

Its value lies in both architectural technology and institutional history. At one end stands craftsmen’s experience of materials, joints, and construction sequences; at the other, official control over project scale, expenditure, and responsibility. Publication in 1103 connected the two more explicitly through words, numbers, and illustrations. It preserved a body of knowledge about government construction, but cannot on its own represent the practices of every region and building type in the Song period.

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