Take the section of the standard timber, the cai, as the module of the building: it is 15 fen high and 10 fen wide, and every member is dimensioned in fen.
1 cai = 15 fen (height) × 10 fen (width)
Rules · Proportion · Columns · Spacing · Façades
The central bay is the widest; columns no taller than a bay is wide
Make the central bay (mingjian) the widest and let the bays diminish toward the ends; keep the eave columns no taller than the width of their bay.
The widening of the central bay marks the entrance and the axis, as the wider central intercolumniation of the eustyle temple does in the West (The five intercolumniations). The limit on column height keeps the proportion of each bay close to a square or a broad rectangle; the bracket zone and the great roof above then make the hall read as low and wide, anchored to its platform, rather than tall.
Related rules
There are eight grades of cai, from 9 × 6 cun down to 4½ × 3 cun; use the first for great halls of nine or eleven bays and the smallest for pavilions and ceiling coffers.
grades 1–8: 9×6, 8¼×5½, 7½×5, 7.2×4.8, 6.6×4.4, 6×4, 5¼×3½, 4½×3 cun
Shape the underside of every arm’s end in four or five facets, and reduce the upper third of a spindle column by the same method, so that no member ends in a hard corner.
For a great hall, measure the distance between the front and back eave purlins and raise the ridge purlin above them by one third of it; for lesser halls, by about a quarter.
rise = ⅓ × depth between eave purlins (halls); ≈ ¼ (+ a small addition) for ting-tang halls
Give a hall an odd number of bays across the front (three, five, seven, nine or eleven) so that the central axis passes through a bay and a doorway, never through a column.
Make each column a little taller than the one nearer the centre, so that the corner columns stand highest: by 2 cun per column outward from the central bay, giving 6 cun at the corners of a seven-bay hall and 1 chi 2 cun for thirteen bays.
corner rise = (bays − 1) cun · each step outward = 2 cun
Cite this page Chris Paton, “The central bay is the widest; columns no taller than a bay is wide”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/mingjian-widest. Text, drawings and models licensed under CC BY-NC 4.0.