An apparatus and method for estimating resource consumption of a household device, e.g., an appliance. The method comprises determining a resource demand profile for a household device for a given time period, the resource demand profile associating, for the given time period, a device state of the household device with a total resource demand for the household. In one embodiment, the apparatus can be incorporated into an energy management system, where the apparatus collects data from each of the appliances in a household as well as from a resource meter.