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.
Never let four corners of mats meet
Lay the mats of a room so that their joints form T-junctions: no point where the corners of four mats meet, and no continuous seam running straight across the room.
The auspicious laying (shūgi-jiki) wheels the mats round the room, typically with a half mat at the centre of a four-and-a-half-mat room. The grid laying (fushūgi-jiki), in which four corners meet in a cross, was associated with funerals and avoided in daily life. The custom is also sound craft: a cross joint lets mats shift and gaps open, while staggered joints lock the floor together, just as bricks are laid in bond.
Related rules
Lay out the royal city as a square of nine li on each side, with three gates in each wall and, within, nine roads running north–south and nine east–west, each wide enough for nine chariots abreast.
side = 9 li · 3 gates × 4 sides · 9 jing + 9 wei · road width = 9 gui (tracks)
Find true north and south with a plumb-lined post and the shadows of sunrise and sunset, checked by the pole star; then turn the principal hall of every compound to face south.
Set stones by first placing a principal stone and then others that answer it, following the “request” each makes; recall famous landscapes; and obey the taboos: a stone that lay flat in nature should not be set upright, nor one that stood upright laid flat.
Where there is no pond or stream, make the landscape of stones alone: set rocks as mountains, cliffs and islands, and let gravel or sand stand for water.
Set out the posts of a house on a square grid of one ken (six shaku, about 1.82 m) and size rooms, doors, screens and mats to fit the grid.
1 ken = 6 shaku ≈ 1.82 m · 1 tsubo = 1 ken² ≈ 3.3 m² = 2 mats
Cite this page Chris Paton, “Never let four corners of mats meet”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/tatami-four-corners. Text, drawings and models licensed under CC BY-NC 4.0.