Geometry and proportion have served as foundational organizing principles in Iranian architecture, particularly evident in the spatial configuration of historic houses in Qom during the Qajar, late Qajar, and Pahlavi periods. This research presents a comparative analysis of spatial proportions in 23 heritage residences, examining dimensional ratios of primary spaces - including courtyards, rooms, three-door (se-dari), and five-door (panj-dari) halls - against three established proportional systems: the golden ratio (1.618), the Iranian golden rectangle (1.73), and the Gaz and Peymon (1.066). Employing an analytical-comparative methodology, the study combines field measurements with architectural plan analysis, utilizing statistical evaluation through ANOVA and one-sample t-tests in R software.
The findings demonstrate that while overarching proportional principles maintained relative consistency across the three historical periods, specific spatial elements exhibited distinct patterns of alignment with the examined systems. Rooms from the Qajar period showed the most consistent correspondence with all three proportional frameworks, while late Qajar reception spaces predominantly adhered to the golden ratio. The Pahlavi era witnessed a return to Gaz and Peymon proportions in courtyard design, likely reflecting contemporary standardization efforts. Notably, courtyard proportions in earlier periods diverged from the studied systems, potentially resulting from land availability constraints, evolving domestic requirements, and broader socio-economic transformations.
This investigation highlights the enduring significance of geometric principles in Persian residential architecture and proposes their thoughtful integration into contemporary design practice. Such an approach offers potential for maintaining regional architectural identity while addressing the climatic demands of Qom’s arid environment. The study contributes to ongoing scholarly discourse on Islamic architectural heritage preservation and adaptive reuse strategies.
