دانشگاه شهید بهشتی صفه 1683-870X 36 2 2026 05 22 Constrained Possibilities: Housing Typology, Regulation and Non Deterministic Evolution of Urban Form in Tehran Constrained Possibilities: Housing Typology, Regulation and Non Deterministic Evolution of Urban Form in Tehran 27 46 106790 10.48308/soffeh.2026.106790 FA Homeira Shayesteh Assistant Professor of Construction, Architecture and BIM, Department of Architecture and Built Environment, Middlesex University, London, United Kingdom 0000-0002-8256-2327 Journal Article 2026 02 22 <strong>Background and Objectives</strong>: The transformation of Tehran’s urban fabric throughout the twentieth century generated a wide spectrum of housing typologies shaped by shifting planning ideologies, regulatory frameworks, and socio-spatial conditions. Existing literature has often interpreted these changes through linear narratives of modernisation or Western influence, neglecting the mediating role of regulation and the significance of intermediate spatial scales. This study aims to examine the evolutionary trajectory of housing typology and urban morphology in Tehran between 1900 and 2000, focusing on the interaction between macro-scale planning mechanisms and micro-scale architectural form. The primary objective is to assess whether housing evolution followed a deterministic path or whether multiple typological outcomes emerged within constrained regulatory and spatial conditions.<br /> <br /><strong>Materials and Methods</strong>: The research adopts a multi-scalar and interdisciplinary methodology integrating urban history, morphological analysis, and empirical spatial investigation. Three representative residential areas of 500 × 500 m, corresponding to distinct phases of Tehran’s urban development, are analysed using Geographical Information Systems (GIS). This is combined with archetypal modelling based on Steadman’s geometric principles to examine relationships between block structure, plot subdivision, density, site coverage, and housing layout. Architectural variables—including access systems, frontage conditions, day-lit depth, and spatial configuration—are systematically evaluated in relation to planning regulations, enabling comparative analysis across historical periods.<br /> <br /><strong>Results and Conclusion</strong>: The results indicate that housing typologies in Tehran were strongly influenced by plot structure, block morphology, and regulatory constraints; however, these influences operated in a non-deterministic manner. Multiple spatial configurations emerged within similar regulatory frameworks, demonstrating a probabilistic relationship between planning rules and architectural form. The transition from inward-oriented courtyard houses to outward-facing row houses and later apartment buildings is therefore interpreted as an adaptive process shaped by functional requirements and regulatory negotiation rather than a direct transplantation of Western models. By foregrounding the intermediate scale of plots, blocks, and housing types, this study challenges reductive interpretations of Tehran’s urban transformation and highlights the coexistence of traditional spatial logics and modern planning systems. The research contributes a robust analytical framework for linking regulation to architectural form and offers insights relevant to contemporary housing policy and urban design.<br />  <strong>Background and Objectives</strong>: The transformation of Tehran’s urban fabric throughout the twentieth century generated a wide spectrum of housing typologies shaped by shifting planning ideologies, regulatory frameworks, and socio-spatial conditions. Existing literature has often interpreted these changes through linear narratives of modernisation or Western influence, neglecting the mediating role of regulation and the significance of intermediate spatial scales. This study aims to examine the evolutionary trajectory of housing typology and urban morphology in Tehran between 1900 and 2000, focusing on the interaction between macro-scale planning mechanisms and micro-scale architectural form. The primary objective is to assess whether housing evolution followed a deterministic path or whether multiple typological outcomes emerged within constrained regulatory and spatial conditions.<br /> <br /><strong>Materials and Methods</strong>: The research adopts a multi-scalar and interdisciplinary methodology integrating urban history, morphological analysis, and empirical spatial investigation. Three representative residential areas of 500 × 500 m, corresponding to distinct phases of Tehran’s urban development, are analysed using Geographical Information Systems (GIS). This is combined with archetypal modelling based on Steadman’s geometric principles to examine relationships between block structure, plot subdivision, density, site coverage, and housing layout. Architectural variables—including access systems, frontage conditions, day-lit depth, and spatial configuration—are systematically evaluated in relation to planning regulations, enabling comparative analysis across historical periods.<br /> <br /><strong>Results and Conclusion</strong>: The results indicate that housing typologies in Tehran were strongly influenced by plot structure, block morphology, and regulatory constraints; however, these influences operated in a non-deterministic manner. Multiple spatial configurations emerged within similar regulatory frameworks, demonstrating a probabilistic relationship between planning rules and architectural form. The transition from inward-oriented courtyard houses to outward-facing row houses and later apartment buildings is therefore interpreted as an adaptive process shaped by functional requirements and regulatory negotiation rather than a direct transplantation of Western models. By foregrounding the intermediate scale of plots, blocks, and housing types, this study challenges reductive interpretations of Tehran’s urban transformation and highlights the coexistence of traditional spatial logics and modern planning systems. The research contributes a robust analytical framework for linking regulation to architectural form and offers insights relevant to contemporary housing policy and urban design.<br />  https://soffeh.sbu.ac.ir/article_106790_a1e6458db64e93a2acde93cc56f834e0.pdf