The contemporary role of libraries has evolved from mere information storage to facilitating engaging access to knowledge resources. Despite this shift, book reading and library usage statistics in Iran remain low. This study aims to explore the relationship between physical and spatial library features, user behaviour, and perceived meanings. The goal of this investigation is to consider the impact of spatial features within libraries on the behaviours of users and the meaning that they receive. Employing an environmental psychology approach, exploratory analyses were conducted through field research, incorporating observational techniques (behavioural attributes mapping and lists) and questionnaire-based methods (semantic differential). Three Shiraz public libraries were selected for observation, and user behaviours were documented. Questionnaire data were analysed using SPSS23 software. Findings indicate that superior physical and spatial attributes foster user attachment to libraries. The meanings of ‘ordered’, ‘pleasant’, ‘interesting’, ‘legible’, ‘open’, and ‘quiet’, along with the physical factors of ‘interior appearance’, ‘type of windows’, ‘outside view’, ‘special decorating’, ‘type of materials’, ‘inviting entrance’, ‘ceiling height’, and ‘furniture’, are influential determinants of user attachment to public libraries.