The aim of this study is to design a nursing home in District 22 of Tehran using an ECLECTIC architectural approach to meet the psychological, social, and physical needs of the elderly. This applied research adopts a descriptive-analytical method using library, documentary, and field-based data. Theoretical and psychological foundations related to aging and elderly care environments were collected from academic sources. Then, through the analysis of domestic and international case studies and the climatic assessment of District 22, site planning was carried out. A physical program was also developed for 250 residents, covering residential, therapeutic, rehabilitation, administrative, service, and cultural spaces, based on architectural standards. Field analysis and the development of the physical program indicated that ECLECTIC architecture, due to its flexibility in form, color, and stylistic combinations, effectively addresses the multidimensional needs of the elderly. SWOT analysis confirmed that District 22 is climatically and environmentally suitable for such a project. The design of interactive spaces, green areas, integration of nostalgic and modern elements, and spatial variety play a key role in enhancing elderly residents’ sense of safety, independence, social interaction, and quality of life. The results show that using an ECLECTIC architectural approach in nursing home design can promote mental health, increase life expectancy, and reduce social isolation in the elderly. This style allows architects to combine climatic, psychological, and cultural principles to create more humane and adaptive environments.