The cord stretched along the diagonal of a rectangle produces as much area as the cords along its two sides together; use this to set out right angles and to make squares of any required area.
d² = a² + b²; e.g. cords of 3, 4, 5 or 5, 12, 13 units
Rules · Plans · Modules · Theory
The site is a squared diagram
Divide the square site into a grid of equal squares (padas), most often 8 × 8 = 64 or 9 × 9 = 81, and place every part of the building according to the grid.
64 padas (maṇḍūka) or 81 padas (paramaśāyika)
The treatises list thirty-two diagrams, from a single square to 1,024, each suited to a kind of building. The 64-square grid, with a line rather than a square at its centre, is used for temples and for sacrificial pavilions; the 81-square grid, with a single central square, for temples, houses and towns. Each pada is the seat of a deity, and the grid gives the builder a way to divide the site into walls, courts, halls and shrine in proportions that are also meaningful.
Actual temples follow the diagrams with varying strictness; they are better understood as generative frameworks than as blueprints.
Related rules
Imagine the vāstupuruṣa lying face down on the diagram with his head in the north-east and his feet in the south-west, held down by the gods who occupy the padas; do not place walls, pillars or doors on his vital points.
Read the diagram from the centre outward: Brahmā at the heart, then a ring of the gods, a ring of human concerns, and on the outside the lesser spirits; the holiest function goes at the centre and the most worldly at the edge.
81 padas = 9 (Brahmā) + 16 + 24 + 32
Place the garbhagriha (the small dark chamber that houses the image) over the Brahmasthana, with its walls on the ring of the gods and its door on the axis, usually to the east.
Provide a path for circumambulation (pradakshina) in the clockwise direction, keeping the sacred object on the right, and enclose it with a railing that separates the sacred ground.
Break each face of the square sanctum into projections (rathas), three, five, seven or more, that step forward towards the central one, and carry them up unbroken through the wall and the tower.
tri-ratha 3 · pancha-ratha 5 · sapta-ratha 7 projections per face
Cite this page Chris Paton, “The site is a squared diagram”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/vastu-grid. Text, drawings and models licensed under CC BY-NC 4.0.