In most homes, the operation of heating and cooling equipment accounts for the largest part of the home's energy bill. Despite this, most homes waste a tremendous amount of this energy through inefficient use. Efficiency can be significantly improved by only activating the heater, fans or air conditioning when you're home and by only heating or cooling to an exact desired temperature.
Automated zoned systems will only heat or cool the room that is being occupied. The occupied room will also be heated or cooled to the desired temperature much faster. This is because the energy that would otherwise be wasted on the unoccupied room is being directed to the occupied room.