The rapid expansion of residential complexes in newly developed towns has highlighted the importance of open and semi-open spaces as key components influencing residential quality and the formation of a community-oriented lifestyle. Accordingly, this study aimed to develop a conceptual model explaining the formation of a community-oriented lifestyle based on the characteristics of open and semi-open spaces in the Azaran Residential Complex, located in Phase One of Sahand New Town, Iran. The research is applied in purpose and exploratory–explanatory in nature and adopts a qualitative approach grounded in Strauss and Corbin’s systematic Grounded Theory methodology. Data were collected through semi-structured interviews with 25 experts in architecture, urban design, urban planning, and environmental psychology. Theoretical saturation was achieved after 22 interviews, while three additional interviews were conducted to ensure data adequacy. Data analysis was performed using MAXQDA Analytics Pro 2025, resulting in the extraction of 256 initial codes, which were subsequently refined into 38 open codes, 10 axial categories, three selective categories, and one core category. The findings revealed that the quality of open and semi-open spaces promotes social interactions and strengthens residents’ sense of place attachment, leading to the development of collective social living as the core process. This process ultimately facilitates the emergence of a community-oriented lifestyle among residents. The proposed conceptual model provides a theoretical framework for designing, planning, and managing open and semi-open residential spaces with the aim of enhancing social sustainability, improving residential environmental quality, and fostering community-oriented lifestyles in new towns.