Rules · Plans · Façades · Geometry
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
The central projection is the bhadra, the corners the karnas, and those between the pratirathas. Their number grows with the size and date of the temple: early shrines are tri-ratha, the mature temples of Khajuraho and Bhubaneswar pancha- or sapta-ratha. Because the projections continue into the tower, the shikhara is not a smooth cone but a bundle of vertical ribs, and the shadows between them draw the whole temple upward.
Set a vertical rod at the centre of the levelled site, draw a circle round it, mark where the tip of its shadow crosses the circle before and after noon, and join the two marks: that line runs east–west.
E–W = chord through the morning and afternoon shadow points; N–S ⟂ through its midpoint
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
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)
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.
Cite this page Chris Paton, “Rathas: the plan in projecting planes”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/rathas-offsets. Text, drawings and models licensed under CC BY-NC 4.0.