In 13th/14th century Ilkhanid, Iran, there occurred a major evolution of the construction industry. Aside from the social and economical situation affecting all construction, there was a deliberate, planned and programmed approach to regulate the construction trade, and to experiment beyond the technological boundaries of the time.
It is Ghazan Khan (1271–1304), the most visionary of Ilkhans, who reformed the construction industry by setting higher standards and effecting quality control. Material mix, quality and prices of building materials were regulated and strictly enforced. Reliable, key individuals were personally responsible for the implementation of building projects. This applied as much to quality control as to the cost of construction and its timely completion. He further implemented a large scale program of rebuilding the devastated country by ordering the construction of an impressive number of public buildings all over the country. This included schools, baths, caravanserais, hospitals, mosques and other religious buildings, as well as irrigation canals, city fortifications and gardens.
The second aspect of this architectural revolution is an attempt to build unprecedented mega-structures. Of these three are well known. The first of these three ambitious projects was the magnificent tomb tower of Ghazan himself built in 1297. He truly intended to build the largest structure of his time and he actively participated in its planning and construction. This building is no longer standing today, but there are several descriptions of this tomb tower to allow a comprehensive understanding of the building. The second mega - structure is the mosque of 'Alishah (dates?) in Tabriz, which consisted of a huge barrel vault with massive walls ten meters in width and twenty-five meters in height.
The third is the mausoleum of Uljaiytu in Sultaniyya (dates?). A masterpiece of structural ingenuity, it is built upon a series of well- designed arches and vaulted spaces that support a unique parallel double shell dome, and an incredible example of the architecture of the void.
These three contemporary large-scale buildings are completely different from each other, and represent three different architectural and structural concepts. This paper will explore the complex architectural and structural diversity of large-scale structures in 13th/14th century Iran. It will also assess the changes that occurred during the second period of Ilkhanid Iran within the construction industry, and the concomitant construction site management issues that had to be resolved.