Cities’ potentials for being volumetric a city-scale comparative approach

Cities are challenged with issues that are related to and land scarcity, rapid population growth, complex terrain, and a lack of updated analytical planning decisions. Traditionally, planners have relied on two-dimensional spatial models rather than more realistic three-dimensional representations of urban reality. In light of this difficulty, volumetric urbanism seeks to improve city planning by considering cities as three-dimensional phenomena influenced by underground systems, multi-level spacing, and vertical expansion. Based on Hong Kong’s well-established volumetric urban structure, this study uses a GIS-based framework to evaluate the readiness and potential for volumetric development in four cities in the Kurdistan Region of Iraq: Erbil, Sulaymaniyah, Duhok, and Akre. The proposed framework links two connected entities: natural contexts, represented by slope and elevation, and man-made contexts, which capture urban physical characteristics and spatial integration. Physical characteristics include building height, VFR, and EVD, while Spatial integration is measured by accessibility and compactness metrics, including closeness, reach, betweenness, and built-up kernel density. The ArcGIS Pro 3.6.0 Suitability Modeler operationalizes all indicators using MCDA. The results show significant volumetric potential differences between case cities. Erbil’s urban pattern is strongly centralized around its historical core, while Sulaymaniyah, Duhok, and Akre offer greater potential for terrain-adaptive vertical densification. Despite the differences in scale, Akre and Hong Kong exhibit comparable volumetric characteristics shaped by terrain and compact urban form. Overall, the results demonstrate how topographical constraints, built-form intensity, and spatial integration influence volumetric transformation, providing a transferable approach for evidence-based and context-responsive urban densification.