Set a mosque’s portal square to the street or square it opens from, but turn the building behind it to face Mecca, and let a vestibule or corridor make the turn between them.
Isfahan: qibla ≈ 225°, i.e. 45° to the Maidan
The Maidan runs roughly north and south, but Mecca lies about 225° from Isfahan. The architects gave each mosque two alignments. The portal of the Masjid-i Shah closes the axis of the square; behind it a domed vestibule turns through 45°, and the court, the four iwans and the domed sanctuary lie at that angle to everything in front of them. At the Lotfollah mosque, opposite the palace, a bent corridor leads from the portal round to the square domed chamber, which again faces the qibla.
The device is common wherever a mosque had to fit an existing street pattern: seen from the city it takes its place in the plan; seen from within it faces Mecca.
To turn a domed square into a long church, open two of its great arches into semidomes of the same radius, and open the semidomes in turn into smaller exedrae, so that the space expands by stages from the central dome.
Hagia Sophia: central square 31 m; two semidomes of radius ≈ 15.5 m; four exedrae; interior ≈ 31 × 70 m
Where the ground is flat and the water lies deep, raise it from wells by wheels into tanks and channels, and lay the garden out in regular, symmetrical plots round them, with walks, beds of flowers and trees in order.
Orient the prayer hall so that its principal wall, the qibla wall, stands square to the direction of Mecca, and mark the middle of that wall with a niche, the mihrab.
qibla wall ⟂ direction of the Kaaba; mihrab on the axis
Place an iwan (a vaulted hall walled on three sides and open on the fourth) at the middle of each side of the courtyard, the one on the qibla side leading to a domed chamber before the mihrab.
Cover the prayer hall with a single central dome on four piers and extend the unified space by semidomes on two or all four sides, with smaller half-domes (exedrae) in their corners.
To make the domed space as nearly one room as possible, set the dome on eight piers inscribed in a square, and fill the four corners with semidomes on the diagonals.
Cite this page Chris Paton, “Portal to the square, prayer hall to Mecca”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/maidan-qibla-turn. Text, drawings and models licensed under CC BY-NC 4.0.