Controlling energy usage of a building. At least one temperature sensor monitors temperature within a zone of a building. A processor determines an off-peak temperature target as a function of a duration of an off-peak operating state of the monitored zone and a desired temperature within the monitored zone during a subsequent peak operating state of the monitored zone. A controller receives the determined off-peak temperature target and is responsive to the received off-peak temperature target to control the temperature within the monitored zone of the building during the off-peak operating state. Other aspects of the invention are directed to computer-readable media for controlling energy usage of a building as described.