An Analysis of Formal Geometry in Typologies and Construction Methods of Isfahan’s Traditional High-Rise Structures; the Case of Freestanding Minarets

Minarets play influential roles in historical cities like Isfahan. They have had a range of functions, and have their distinct architectural, structural and ornamental characteristics. The underlying belief in this research is that the formation of Isfahan’s minarets’ components is directly influenced by brick-laying models, master masons’ skills, plan forms and ornaments. The present research aims at introducing components of the minaret and studying examples of it in Isfahan, and thereby analysing their form and execution. Descriptions are given from functional, structural and formal points of view. Typological studies and classifications are complemented by construction analyses. Data is collected through library studies, on-site observations and surveys and interviews with master builders. These are followed by extracting geometric, typological and structural orders through 3D modelling. Minarets and their components are initially introduced, in order to then focus on their typologies based on their location, number of floors, plan form, overall form, stairway and base, and eventually construction methods. The findings show that plan-wise Isfahan minarets are clockwise, circular, with their external wall thickness increasing with their overall height. Volume-wise the city’s freestanding minarets are cylindrical or part-conical both with and without a base. There are two types of timber restraints used in these minarets with external walls constructed vis-à-vis stairways to provide structural integrity ('Hasht and Gir').