Academic Libraries (ALs) design concept has been under a changing process, precipitated by both internal needs and external pressures including changes in the societal context of education, the information services and documentation storage requirements. This paper is focused on a model of form and function to assess AL’ in use, in order to explore ways for better understanding their performance. The proposed model was developed within the scope of a wider research project and makes both use of Post-Occupancy Evaluation and of Space Syntax procedures in order to explore how the spatial configuration influences the performance and use of ALs space. It considers ALs building typology as spatial, physical and social systems, by: 1) measuring users satisfaction about how well the space supports their requirements; and 2) providing information on how architecture and spatial design support - enable and generate - flows of information, communication and knowledge.The analysis provides evidence suggesting that ALs’ spatial system influences study performance, patterns of use and co-presence of its users. The results of data inputs point out prospective strategies about space intervention.