The four-iwan mosque
Isfahan: a courtyard with an iwan in the middle of each side, pishtaq portals, and a double-shelled dome over the qibla chamber.
The rules it illustrates
The four-iwan court. 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.
The pishtaq. Set the iwan arch in a tall rectangular screen that rises above the roofline, framed by bands of inscription and flanked by minarets.
The double dome. 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.
Where it appears in the book
In the styles Persian Islamic (Seljuk, Timurid and Safavid).
In the chapters The Islamic World.