<p>This article examines the current state of the intelligent building monitoring system created for the University of Santiago de Compostela (USC) in the framework of the OPERE european project and proposes a modification based on the Fog Computing paradigm. The study carried out in the present paper is developed in the context of the European regulations on energy efficiency of installations and reduction of greenhouse gases. The current system implements data processing in DADIS modules, developed by this research group, for the flexible acquisition and transmission of information. These modules provide information to the monitoring system that offers functionalities such as energy consumption dashboards, configurable operating schedules, and ad hoc data visualization, among others. However, the current system has some limitations, including the difficulty in scaling the processing of acquired information and database queries. A system upgrade is proposed that leverages fog processing capabilities through microservices-based development, with each microservice has a specific responsibility and is deployed as an intermediate layer between the sensors and the application. The clarity and maintainability advantages of the resulting architecture are analyzed, and it is proposed that this architecture could support big data infrastructures to address more complex problems than those described in this scenario.</p>