Europe's latest energy framework aims to decrease energy consumption and mitigate carbon dioxide emissions while regulating thermal comfort for the occupants through Home energy management systems (HEMSs) or Building Management Systems (BMSs). In this paper, a practical approach for IoT interconnecting sensors and actuators to a BMS is presented. The architecture is based on a centric BMS, communicating with numerous IoT gateways, while various widely used communication protocols are interlinked to the gateway networks, facilitating the system's interoperability and integration. Moreover, energy saving actions may be handled by the proposed system and specific controls may be sent by the BMS to the actuators to perform automatic energy saving commands. During the experiments, various tests were deployed to verify the system's perpetual operation.