Since the quality of apartment buildings is noted, the way of increasing attachment and discovering its effective variables is challenging subjects for researchers in this field. Person, place and process (P.P.P) model of place attachment as the most precise model of them, evaluate attachment to three parts of person, place and process. What is going to be studied in this research is to evaluate attachment of residents to the open space of such buildings. Then, identifying the effective variables and suggesting practical solutions to improve quality of such environment are the subsequent goals of this research. This is practical research with correlational cases study method.used for Ekbatan and Iran Zامین apartment buildings and SPSS is used to analyze data. The findings show that in both cases, attachment is in high degree while physical and social attachment in Iranzامین apartment building is more than Ekbatan. In addition physical attachment is more than social attachment in both cases. The results show that in personal dimensions, designers should pay attention to the expectations and variety of needs for different ages of residents. In place dimensions, type of territories, accessibility, and flexibility of spaces in designing open spaces are the key points for designers. In addition, the way these types of buildings are managed is so important in the process of place attachment that shows it is needed for their managers to have some special skills to respond to the mobility character of place attachment.
