BACnet (Building Automation and Control Networks) is a very powerful BUS for building automation. The network protocol has been standardized in such way that communication across application profiles is possible. The development of the system began in 1987 and was under leadership ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers). This standard is primarily designed for complex and especially for large projects, so that all levels of a project can be covered. This begins with the sensors and so-called IO’s at the field level, via the controllers and their networking (automation level) and ultimately the administration level, i.e. the building management system, in order to manage the project with all its tasks. For a normal smart home, this system is probably "one number" too big. Of course in BACnet there are very extensive integration options. Since this system is often mentioned in connection with building control, at least it should been mentioned.