The aim of this study was to present that it is possible to design and implement an efficient and functional intel-ligent building management system based on free tools, own project and self-realization of sensor network sys-tem which may be a low cost alternative to commercial ones. The paper presents the designed system consisting of implemented devices on the basis of sensor network technology and own hardware project in a building manage-ment system. At the application level there was designed and implemented the building management system which allows communication between the sensors, data exchange between the sensors and the database as well as the system parameters visualization panel used for intelligent building monitoring.