An energy management system includes an energy management apparatus configured to mange energy supplied to equipment devices of a plurality of buildings, and a control apparatus configured to control the equipment devices in the buildings. The energy management apparatus is located superordinate to the buildings. The control apparatus is connected to the energy management apparatus. The control apparatus includes an operating status perceiving unit configured to perceive operating status of the equipment devices, and a reducing capability presentation unit configured to present a plurality of energy reducing capabilities for at least one condition to the energy management apparatus. The energy reducing capabilities are amounts of energy that can be reduced for the equipment devices based on the operating status perceived.