An analysis of urban development plan regulations influencing housing construction trends in different district of Tehran

Urban development plans constitute essential policy frameworks through which public authorities manage and guide the dynamics of urban growth, particularly in the housing sector. These instruments not only shape the spatial form of cities, but also regulate how housing production responds to demographic pressures, land market behavior, and socio-economic transformations. In the context of rapidly expanding metropolitan regions, such as Tehran, urban development plans are expected to serve both as a strategic vision and a regulatory tool to ensure that growth is aligned with the goals of social equity and affordability.
Over the past two decades, Tehran has experienced significant changes in its housing and construction patterns, largely influenced by the implementation of two major planning documents: the Strategic-Structural Development and Urban Planning Plan of Tehran (Tehran Master Plan) (approved in 2007) and the Detailed Plan (approved in 2012). The aim of these plans was to provide a comprehensive framework for spatial organization of the city, control construction intensity, and balance housing supply with population growth and income distribution. However, the actual results of these planning interventions are still a matter of debate. During the same period, Tehran witnessed a steady increase in housing prices, a sharp increase in the housing affordability index, and increasing inequality in access to adequate housing. The index – measured as the ratio between the cost of purchasing an average 75 square meter residential unit and the average household income – showed that housing affordability had fallen to unprecedented levels. In fact, the market increasingly favored larger, more expensive units rather than stimulating the production of smaller, more affordable housing units in line with household purchasing power. This divergence between policy goals and market behavior raises important questions about the actual effectiveness of Tehran’s urban planning tools in steering the housing market toward inclusive and balanced outcomes. This suggests that despite the formal presence of regulatory systems, the urban development process in Tehran is still largely driven by speculative forces and uncoordinated market dynamics.
This study aims to examine how the regulatory frameworks contained in the Tehran Master Plan affect housing production patterns over time, through a longitudinal impact assessment. Assuming that municipal building permits were issued in accordance with these regulations, this study compares the characteristics of housing construction in two distinct periods: 2006–2011, representing the pre-implementation phase, and 2012–2018, representing the post-implementation phase. This study, by analyzing data of building permits issued in all 22 districts of Tehran Municipality, seeks to reveal temporal and spatial variations in housing production volumes, unit characteristics, and land-use efficiency. The main hypothesis of the research is that while the Detailed Plan may have imposed stricter controls on building activities, its regulatory approach may have unintentionally led to a reduction in housing diversity and affordability.
Methodologically, this research uses a quantitative and longitudinal comparative analysis  focusing on two main groups of indicators: Group A includes indicators related to the volume of housing production, including the total number of permits issued, total floor area, and the distribution of residential construction across city districts. Group B includes indicators that reflect the physical and architectural characteristics of the units produced – such as the average floor area per dwelling unit, the ratio of unusable (non-operational) to usable space, and the land-to-unit ratio. Together, these indicators allow for a multidimensional assessment of how planning regulations affect the quantity and qualitative composition of new housing stock. The findings reveal a set of non-rational results. Together, these indicators allow for a multi-dimensional evaluation of how planning regulations have affected both the quantity and the qualitative composition of new housing stock.The findings demonstrate a set of counterintuitive outcomes.
 
The post-implementation period (2012–2018), which coincided with a housing market downturn, exhibited a significant decline in the volume of housing production in almost all districts. However, rather than improving affordability, this decline was accompanied by a shift towards larger average unit sizes and a reduction in housing type diversity. The dispersion of residential lots – an indicator often associated with small, affordable construction – decreased significantly after 2012, indicating that fewer but larger lots were built. At the same time, the share of non-functional area increased, indicating a design and construction approach that was less responsive to the needs of affordability and everyday functionality. These results suggest that although the detailed plan may have been successful in exerting formal control over building density and land subdivision, it has failed to guide development towards community-responsive housing outcomes. From a policy perspective, these findings have several important implications. First, they indicate that the regulatory frameworks embedded in Tehran’s urban development plans, though intended to rationalize construction and guide urban growth, have not effectively addressed the mismatch between household income levels and housing production. Rather than promoting compact, affordable, and diverse housing patterns, these regulations appear to have reinforced existing inequalities by favoring larger and more luxurious units. Second, empirical evidence highlights the limited adaptive capacity of static planning tools in contexts characterized by volatile market conditions and speculative pressures. The inability of the detailed plan to respond dynamically to market signals highlights the need for a more flexible and demand-sensitive planning approach. Finally, the results emphasize the importance of integrating housing affordability considerations directly into the regulatory logic of urban development plans, rather than treating them as secondary objectives. Second, the empirical evidence highlights the limited adaptive capacity of static planning instruments in contexts characterized by volatile market conditions and speculative pressures. The inability of the Detailed Plan to respond dynamically to market signals underscores the need for a more flexible, demand-sensitive planning approach. Finally, the results emphasize the importance of integrating housing affordability considerations directly into the regulatory logic of urban development programs, rather than treating them as secondary objectives.
In conclusion, this study provides a critical assessment of how the city’s housing production landscape has been shaped by Tehran’s urban planning regulations over a 13-year period. This study shows that despite the existence of comprehensive and detailed master plans, the desired policy outcomes—namely, improving affordability, diversity, and balanced spatial distribution of housing—have not been achieved. The evidence suggests that regulatory interventions alone, when not supported by targeted economic incentives and strong monitoring mechanisms, are insufficient to align housing production with broader urban equity goals. This research recommends a two-pronged strategy for future planning efforts in Tehran and other rapidly urbanizing contexts: (1) Strengthen the integration of housing affordability indicators into land use planning and control systems, and (2) develop adaptive monitoring mechanisms capable of responding to market dynamics in real time.
By providing empirical evidence and conceptual insight, this study contributes to the broader discourse on the interrelationship between urban planning regulations and housing outcomes, demonstrating that the success of urban development programs depends not only on their formal existence, but also on their practical adaptation, inclusiveness, and responsiveness to local socio-economic realities.