Structural System Choice Patterns and Their Association with a Height Proxy Based on National Building Permit Data of Iran (Year ۱۴۰۳)

The selection of structural systems in urban construction involves a complex interplay of regulatory standards, engineering capabilities, economic limitations, and local construction norms. In Iran, reinforced concrete (RC) and steel frames dominate the new construction landscape; however, a systematic analysis of how these preferences differ across provinces― and how they correlate with building height-remains underexplored. This paper utilizes national building permit data for the year ۱۴۰۳ (Hijri Shamsi) to investigate structural system trends at the provincial level. A proxy for building height is introduced by calculating the proportion of permits issued for buildings with three or more stories. Structural system shares-categorized as RC, steel, and others—are derived from unit-level data. To incorporate physical scale, an additional variable, Area per Unit (m²/unit), is defined as the total built floor area divided by the number of residential units. The analytical process includes data preprocessing, descriptive exploration, median-based quadrant classification, correlation assessment, and multivariate clustering using K-means with Z-score normalization and PCA visualization. The results highlight significant regional variability in both structural system preferences and the height proxy. Moreover, the inclusion of Area per Unit enhances the differentiation of provincial construction typologies. These findings offer valuable insights for national-level planning regarding construction resources, capacity management, and monitoring trends in the building sector.

کلیدواژه ها:

building permits ، structural systems ، reinforced concrete ، steel structures ، height proxy ، clustering