Abstract: An automatic system for controlling the environmental conditions in a building divided into a plurality of zones includes a control station that sends control signals over the power lines of the building to control power consuming appliances in the various zones. The control station includes a programmable computer that is operably coupled to various displays and control switches on a control panel. In one mode of operation the switches and displays are utilized to program a schedule into the computer for controlling the various power consuming appliances such as heating and airconditioning units, lights, machinery and the like in order to provide a desired environment within the various zones of the building.