Quick Answer: What Is a Jian in Chinese Architecture?
A jian (间, jiān) is a bay in traditional Chinese timber architecture. On a facade, it is the interval between adjacent columns. In plan, the bay includes the space back to the next row of columns. Four columns in one straight row mark three intervals.[1]
- Count: Follow a row of columns and count the gaps.
- Measure: Use the distance between column centerlines.
- Read the space: An open hall may extend across several bays.
The Forbidden City’s Hall of Supreme Harmony is eleven bays wide and five deep in the Palace Museum’s description. The figures describe the column layout.[2][3]
When a museum caption says a hall is five bays deep, the number tells you something about its timber frame. To see it in a building, follow the columns and the intervals they set out across the front and from front to back.
How Columns Define a Bay
A column marks one edge of a bay, and its neighbor marks the other. The space between them can be open, fitted with a screen or filled with part of a wall. Columns can still identify a bay when its infill differs from the next one. A garden doorway or threshold marks a crossing for people. Counting the bays is a way of reading the structure around those crossings.
The same principle applies in plan. Locate two neighboring column lines in each direction. The bay is the part of the floor between them. Architectural historian Nancy Shatzman Steinhardt uses the interval across the front and the space behind it to explain the unit in his study of Chinese building standards.[1]
Doors give an uncertain count. Two leaves can open within one interval. A bay can have a window or no opening at all. If the posts are hidden behind fittings, a reliable floor plan can make their positions clearer.
Width, Depth and the Central Bay
The Palace Museum glossary defines miankuo (面阔, miànkuò), bay width, as the distance between the centers of adjacent eave columns along the direction of the purlins. Jinshen (进深, jìnshēn), bay depth, is the equivalent measurement in the front-to-back direction. The overall width and depth are the respective sums.[2]
In a building with a distinct central bay, it is called the mingjian (明间, míngjiān). In a symmetrical facade with an odd number of bays, it lies on the main axis. The Palace Museum describes the spaces beside it as secondary bays.[2] Steinhardt’s discussion of the Song-period building manual explains a hierarchy in which the central interval is wider and intervals decrease symmetrically toward the ends.[1]
The count and the distance answer different questions. Two five-bay facades can have different total widths, and neighboring bays within one building can differ in width. The description “five bays” needs measurements to express the actual width in meters.
Counting Bays at Two Forbidden City Buildings
The Palace Museum gives the Hall of Supreme Harmony eleven bays across and five in depth. It identifies the throne with the central bay.[3] That is an example of how the axis of the frame corresponds to the arrangement of a ceremonial interior.
The museum describes Wenyuan Pavilion as six bays wide, with a stair in the westernmost bay linking levels.[4] A library with six bays and a ceremonial hall with eleven both use the same method of description. Their names supply additional information, as the guide to dian, tang and ge explains.
Use the quoted counts to read the plan and the role of particular intervals. Dividing a facade by its visible doors or multiplying the two numbers to estimate rooms would give a different result.
FAQs About Chinese Jian Building Bays
Does one jian mean one room?
A bay is set out by column positions. One room may occupy several bays, and a bay can contain a wall or internal partition.
Do jian all have the same width?
No. The central interval can be wider than others. Actual widths depend on the building, so counts and measurements should be read separately.[1][2]
Do Chinese buildings always have an odd bay count?
No. Odd counts are common in symmetrical layouts with a central bay. The Palace Museum gives Wenyuan Pavilion an even count of six.[4]
Sources
[1] Nancy Shatzman Steinhardt. Chinese Architecture: A History, The Chinese Building Standards
[2] The Palace Museum. Jingfu Palace and the Architectural Glossary
[3] The Palace Museum. Hall of Supreme Harmony
[4] The Palace Museum. Wenyuan Pavilion