Analysis of Threshold Space Patterns in the Historic Fabric of Babol Based on Alexander’s Theories

Over time, from the mid-Qajar period to the first decade of the Pahlavi era, public and private spaces, the spatial hierarchies between these two, and their forms underwent transformations, leading to the emergence of a hybrid style. One of the spaces that has experienced such transformations is the threshold space. As both a concept and a physical structure, the threshold space can encompass a wide range of meanings connected to customs and culture, imbuing the space with distinctive qualities. The significance of threshold spaces lies in their accessibility to public spaces, their integration with private spaces, and their role in shaping the quality of the urban environment. Christopher Alexander, in his Nature of Order series, refers to this concept and highlights the importance of thresholds as a sophisticated architectural element.

The purpose of this article is to analyze the ground and first floors of residential areas in terms of their relationship with public spaces on the scale of buildings, as well as the connections between neighborhoods and buildings on the scale of streets. The study aims to align these findings with Christopher Alexander’s theories on thresholds. Accordingly, this research primarily focuses on threshold spaces and investigates the patterns between these two components based on Alexander’s theoretical framework.

The methodology of this research is qualitative. Data was collected through desk research, interviews, analysis of historical documents (e.g., records, maps, and photographs), personal observation, photography, mapping, and analysis of the current state of threshold spaces. The historical core of Babol city, located in Mazandaran Province, was selected as the case study for this research.

The findings reveal that, during the Qajar era, the hierarchical access to private spaces from urban public spaces, as well as the connections between residential neighborhoods, aligned with Christopher Alexander’s theory. Spatial arrangements were appropriate to and consistent with the customs, culture, and needs of the inhabitants, despite the influences of modernity on the architecture of that period.