A Building Management System, BMS, domotics and Internet of Things, loT, system including a system hardware controller and a first plurality of sub-systems connected to the system hardware controller, which first plurality of sub-systems comprises in turn a sub-system for tasks requiring a high level of security and a second plurality of sub-systems; wherein the system hardware controller comprises: a central processing unit, CPU; a volatile memory; a non-volatile memory (3, 4, 5); a display and user interface composed of video display and human input device; and a plurality of communication hardware interfaces; wherein each sub-system of the first plurality of sub-systems includes sensors and actuators; wherein the sub-system for tasks requiring a high level of security includes also a controller interfaced with the system hardware controller and with the actuators and sensors of the same sub-system for tasks requiring a high level of security; wherein the sub-systems of the first plurality of sub-systems are configured to use different field communication protocols, and wherein the plurality of communication hardware interfaces is configured to connect directly to peripheral field devices of the second plurality of subsystems of the BSM, domotics and IoT system; the system hardware controller is configured to run parallelly different applications - programs, each one responsible for one sub-system; the system hardware controller is interfaced with the actuators and sensors of the subsystems of the second plurality of sub-systems using plural field communication protocols by means of the plurality of communication hardware interfaces of the system hardware controller, characterized in that the system hardware controller is configured to regulate and supervise an entire BSM, domotics and IoT system without support of other controllers, except tasks requiring a high level of security a central processing unit, CPU; a volatile memory; a non-volatile memory (3, 4, 5); a display and user interface composed of video display and human input device; and a plurality of communication hardware interfaces; wherein each sub-system of the first plurality of sub-systems includes sensors and actuators; wherein the sub-system for tasks requiring a high level of security includes also a controller interfaced with the system hardware controller and with the actuators and sensors of the same sub-system for tasks requiring a high level of security; wherein the sub-systems of the first plurality of sub-systems are configured to use different field communication protocols, and wherein the plurality of communication hardware interfaces is configured to connect directly to peripheral field devices of the second plurality of subsystems of the BSM, domotics and IoT system; the system hardware controller is configured to run parallelly different applications - programs, each one responsible for one sub-system; the system hardware controller is interfaced with the actuators and sensors of the subsystems of the second plurality of sub-systems using plural field communication protocols by means of the plurality of communication hardware interfaces of the system hardware controller, characterized in that the system hardware controller is configured to regulate and supervise an entire BSM, domotics and IoT system without support of other controllers, except tasks requiring a high level of security