Urban Morphology and the Social Potential of Space: A Form-Based Reading of the Saadi Informal Settlement, Iran
Abstract
1. Introduction
2. Literature Review
2.1. Social Sustainability in the Context of Informal Settlements
2.2. Urban Morphology: The Physical Dimension of Social Potential
2.3. Space Syntax and Configurational Logic
3. Methodology
3.1. Case Study Context: Saadi Neighborhood
3.2. The Analytical Framework: Form as a Proxy for Social Logic
- Location & Topographical Context (Macro-Scale): This indicator analyzes the settlement’s natural boundaries and siting. It is evaluated for its capacity to create “territorial anchoring”—the degree to which physical enclosure fosters a distinct sense of place and community identity. This indicator draws on Newman’s [28] foundational concept of defined territories, which has been identified by Samper et al. [19] as a critical factor for social stability in informal settlements.
- The Urban Fabric & Network Configuration (Meso-Scale): This component analyzes the interaction between the street network and the urban grain. Drawing on Space Syntax principles, the analysis focuses on how the fine-grained texture and intersection density drive “walkability and co-presence.” As argued by Hillier and Hanson [21] and Askarizad and Safari [7], higher network integration directly correlates with increased potential for social interaction. Simultaneously, the analysis identifies semi-private clusters (cul-de-sacs) that function as “defensible space,” providing safe territories for vulnerable groups as observed by Kamalipour and Peimani [12]. Key metrics include movement hierarchy and intersection density, established predictors of social interaction [32].
- Building Typology & Verticality (Micro-Scale): This indicator examines the interface between the private dwelling and the public street, as well as the height of structures. It assesses the “visual permeability” of frontages to evaluate the potential for “informal surveillance.” This aligns with Jacobs’ [29] theory of ‘eyes on the street,’ where low-rise, active frontages foster a self-regulating environment of safety, a relationship recently quantified in urban morphology by Mehaffy et al. [5].
- Materiality & Construction (Micro-Scale): This indicator interprets the physical fabric as a semiotic system. The transition from temporary to permanent materials is analyzed as a marker of “social embeddedness” and territorial claim. This proxy is grounded in Turner’s [30] theory of incremental housing, where material consolidation serves as tangible evidence of a resident’s long-term investment and commitment to the community structure [33].
3.3. Data Collection and Procedural Steps
- Step 1: Geospatial and Network Analysis: High-resolution satellite imagery (0.5 m resolution) and municipal base maps were utilized within a GIS environment (ArcGIS 10.8) to digitize the urban fabric. A detailed network analysis was conducted to categorize circulation paths into a functional hierarchy. This categorization allowed for the evaluation of network integration and the identification of “deep” spaces versus “integrated” axes, interpreting the configurational logic of the settlement without relying on purely abstract simulations [13].
- Step 2: Morphological Mapping: Detailed figure-ground and urban grain maps were produced using CAD and GIS tools to quantify the density and texture of the fabric. These maps highlight the “fine grain” and high building coverage ratio that support pedestrian permeability and social intimacy.
- Step 3: Fieldwork and Ground-Truthing: Systematic field surveys were conducted to validate the spatial data. This involved photographic documentation of social behaviors in different spatial types to corroborate the link between the identified spatial configuration and observed social interaction patterns [5].
4. Results: The Social Potential of Saadi’s Morphology
4.1. Macro-Scale: Topographical Enclosure and Territorial Anchoring
4.2. Meso-Scale: Urban Fabric Driving Walkability and Defensible Space
- Walkability and Co-presence: The street network is characterized by a “deformed grid” structure with a high density of intersections and short street segments. Combined with the fine-grained urban texture—identified in [14] as a key determinant of informal morphology—this creates a highly permeable network that naturally slows down traffic and prioritizes pedestrians. Albabely and Alobaydi [34] emphasize that such network properties, particularly connectivity, are the strongest insights for predicting urban pedestrian movement densities. In configurational terms, this morphology drives “walkability” and increases the probability of “co-presence” and casual social exchange (Figure 4). The analysis confirms that the integrated collector streets function as the social spine where public life converges. This reflects Mehta’s [35] taxonomy of sociability, where street characteristics directly invite staying and interaction.
- Defensible Space in Semi-private Clusters: A pervasive feature of the fabric is the abundance of cul-de-sacs (indicated by the blue lines in Figure 5) branching off the local streets. While conventional planning often criticizes these as “segregated,” the analysis reveals their vital social function as “defensible space.” This observation is consistent with Iranmanesh and Kamalipour [36], who describe the morphogenesis of access networks in informal settlements as a process that naturally creates hierarchical zones of privacy. These semi-private clusters create protected territories where 5–10 households share a common zone, supporting the formation of micro-communities.
4.3. Micro-Scale: Verticality and Visual Permeability
4.4. Micro-Scale: Materiality as Social Embeddedness
5. Discussion
5.1. The Social Logic of Organic Form: Synergy of Configuration and Activity
5.2. Morphology as a Buffer Against Socio-Spatial Inequality
5.3. Implications for Practice: From Regularization to Surgical Upgrading
5.4. Rethinking Informality Through Social Potential
6. Conclusions
6.1. Synthesis of Findings
6.2. Policy Implications: Towards Morphologically Sensitive Upgrading
- Recognizing Spatial Assets: Identifying and protecting the integrated pedestrian spines and semi-private clusters as essential social infrastructure.
- Surgical Intervention: Instead of generic infrastructure provision, interventions should be acupunctural and specific. For example, paving and lighting the “integrated” collector streets identified by Space Syntax can boost their function as economic spines. Conversely, in the deep cul-de-sacs, interventions should focus on stabilizing slopes and providing small-scale communal water points or pocket parks, reinforcing their role as safe play areas for children without disrupting the private social fabric [43].
- Enabling Incrementalism: Supporting the user-led process of consolidation through tenure security and technical assistance, acknowledging that the physical solidification of the fabric is a proxy for social stability [19].
6.3. Future Research Directions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
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Nezhadmasoum, S.; Vehbi, B.O. Urban Morphology and the Social Potential of Space: A Form-Based Reading of the Saadi Informal Settlement, Iran. Sustainability 2026, 18, 314. https://doi.org/10.3390/su18010314
Nezhadmasoum S, Vehbi BO. Urban Morphology and the Social Potential of Space: A Form-Based Reading of the Saadi Informal Settlement, Iran. Sustainability. 2026; 18(1):314. https://doi.org/10.3390/su18010314
Chicago/Turabian StyleNezhadmasoum, Sanaz, and Beser Oktay Vehbi. 2026. "Urban Morphology and the Social Potential of Space: A Form-Based Reading of the Saadi Informal Settlement, Iran" Sustainability 18, no. 1: 314. https://doi.org/10.3390/su18010314
APA StyleNezhadmasoum, S., & Vehbi, B. O. (2026). Urban Morphology and the Social Potential of Space: A Form-Based Reading of the Saadi Informal Settlement, Iran. Sustainability, 18(1), 314. https://doi.org/10.3390/su18010314

