EIB:

Practically from the (very primitive) start, mains systems in private homes have had switches to enable loads to be connected to or disconnected from the electricity supply. With relatively few apparatus and lamps in the 'old' days, the number of mains connections in each home was also quite small. That has changed dramatically in the course of time. Not only the number of connections has gone up considerably; ease of use has also become the prime requirement for electrical appliances. Consequently, the need of an intelligent bus system for automation purposes in buildings in on the rise.