Build the tower for the call to prayer in the form of the regional tradition: square and stepped in the Maghreb and Spain, cylindrical and tapering in Iran and Central Asia, needle-like and polygonal in the Ottoman lands.
Rules · Façades · Roofs · Ornament
Crown the roof with chhatris
Mark the corners of roofs, minarets and gateways with chhatris: small open domed kiosks on columns with a projecting eave.
The chhatri (“umbrella”) comes from the Indian tradition (it is the pavilion over a cremation site or a royal seat), and the Mughals made it the characteristic crown of their buildings. It softens the skyline, frames the principal dome in a group of smaller ones, and turns a minaret into a lookout. Its deep sloping eave (chhajja) throws a line of shadow that is one of the constants of Indian architecture.
Related rules
To draw a star pattern, cover the surface with a tiling of polygons, draw two lines through the midpoint of every edge at the same angle to it, continue each line until it meets another, and erase the tiling.
pattern = tiling + contact angle θ at every edge midpoint
Keep the grid and vary the angle at which the lines cross the edges: a small angle gives broad, blunt stars; a large one gives slender, sharp stars.
Choose the symmetry of the principal star (six-, eight-, ten- or twelve-fold) and build the field from a repeat unit that tiles the plane; stars that cannot tile by themselves are completed by secondary shapes in the gaps.
Set the iwan arch in a tall rectangular screen that rises above the roofline, framed by bands of inscription and flanked by minarets.
Build two domes, one above the other: an inner shell proportioned to the room below and an outer shell raised on a tall drum and proportioned to the city outside.
outer crown ≫ inner crown; the gap may be a third of the total height
Cite this page Chris Paton, “Crown the roof with chhatris”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/chhatri-crown. Text, drawings and models licensed under CC BY-NC 4.0.