University campuses can be considered as small towns due to their size, number of users and mixed and complex activities, including numerous actions usually met in urban environments. The energy and environmental impact of universities could be considerably reduced by applying organizational, technological and energy optimization measures. The aim of the present paper is to present an efficient web based energy management system for Campuses which manages in an energy efficient way the Campus buildings and spaces of public use, monitors the energy load and performs energy analysis per building and for the Campus as a whole, as well as it interacts with each building's BEMS and each user through questionnaires, e-mails and forms. The existing Campus IP infrastructure is exploited by using sensor networks, where nodes communicate their information using Web services, allowing direct integration in modern IT systems. To guarantee the system scalability and respect consolidated and diffused standards, the logical/architectural level of the whole Campus Energy Management System is linked with the existing infrastructure based on Internet Protocol (IP). The overall installation is tested via on line questionnaires to the building users showing a significant increase of the occupants' satisfaction. Finally, the energy efficiency achieved by the proposed system is almost 20%. (C) 2016 Elsevier B.V. All rights reserved.