The Role of Infill Architecture Components in Enhancing Neighborhood Identity Based on the Interaction Between New Spaces and Physical Heritage (Case Study: Chidzari and Nimad Buildings in Tehran)

Contemporary physical development in historic urban fabrics, especially in major cities like Tehran, can have negative impacts if contextual structures and characteristics are overlooked. Such development often leads to spatial fragmentation, loss of cohesion, and a weakening of neighborhood identity. Infill architecture is proposed as an effective and innovative approach in these settings. It aims to redefine the connection between past and present by preserving spatial continuity and improving the quality of the environment. This approach also allows new architectural elements to adapt to and interact with existing heritage.

This research investigates the role of infill architecture in enhancing neighborhood identity. The study is based on three theoretical hypotheses. The first is that contextual compatibility strengthens physical continuity. The second is that environmental psychology dimensions contribute to improved subjective perception among users. The third hypothesis is that development and conservation, when balanced, create harmony between new spaces and historic values. The research assesses the performance of these components in both the objective and subjective dimensions of neighborhood identity.

A mixed-methods, applied research design was used. In the first phase, theoretical components were derived through qualitative content analysis of the literature using MAXQDA. To measure the variables and extract strategies, an open-ended questionnaire was administered to domain experts, and their responses guided development of a structured instrument. Next, quantitative data were gathered from residents and experts using a Likert-scale survey. Additionally, two case studies—the Chidzari and Nimad buildings within Tehran’s historic urban fabric—were chosen as practical exemplars. This dual approach enabled evaluation of how the theoretically derived components manifest in real contexts and provided empirical grounding for assessing their applicability and performance in practice.

Data were analyzed using SPSS software. Several statistical methods were employed, including correlation analysis, analysis of variance, and group comparison tests. The findings from both qualitative and quantitative approaches indicate that infill architecture, when implemented with attention to contextual principles and the psychological and social needs of residents, can significantly strengthen both the objective and subjective aspects of neighborhood identity. The objective aspects include physical continuity and compatibility with the historical setting. The subjective aspects involve sense of belonging, perception of identity, and collective memory.

The results underscore the importance of preserving physical continuity, adapting strategies to the local context, and fostering active interplay between new and historic spaces. Furthermore, the comparative analysis demonstrated that residents, placing greater emphasis on the psychological dimensions of neighborhood identity, attained higher mean ranks in the Mann–Whitney U test, whereas experts concentrated more on design principles and physical coherence. Given the limited expert sample, these findings should be interpreted with caution, and further research is required to enhance their generalizability.

Overall, the study underscores that successful infill architecture in historic urban areas depends on a collaborative, holistic strategy aimed at preserving heritage, enhancing environmental quality, and fostering residents’ sense of belonging. In doing so, it offers a viable model for sustainable neighborhood development and practical guidance for planners and architects integrating new interventions into historic contexts.