Iranian architecture of the past is distinguished by its consistent application of geometric rules and mathematical principles, which endowed structures with visual richness and precision. This knowledge was fundamental to historical architectural practice but has diminished in contemporary Iranian design. Geometry remains a key organizing factor in classifying traditional Iranian architecture, with shared principles evident across building types such as bazaars, houses, mosques, and caravanserais.
Among these, traditional baths (hammams) represent an important typology, combining durability, environmental regulation, beauty, and functionality. During the Qajar period, Qazvin served as a major transit hub on the Silk Road, resulting in urban expansion and the construction of neighborhood baths across its twenty districts. These structures evolved from ancient ritual and social functions into significant public amenities, especially under Islamic emphasis on purification.
This study investigates whether specific geometric shapes and proportional systems governed the design of the two primary physical components—Sarbineh (changing room) and Garmkhaneh (hot room)—in nine Qajar-era baths in Qazvin. Employing a mixed-methods approach combining interpretative-historical, survey, and logical reasoning analysis, the research examines architectural layouts and dimensional ratios.
Findings indicate varied use of proportional systems. The √3 ratio appears least frequently, observed only in the length-to-width proportion of Garmkhaneh plans. The dominant pattern across both components is the square proportion (1:1 ratio), particularly evident in the dimensions of length versus width. This suggests a consistent geometric logic underpinning the spatial organization of Qajar baths in Qazvin, affirming the enduring role of structured proportion in Persian architectural heritage.
