With growing concerns about climate change and increasing energy costs, energy-efficient use of buildingsoffers an opportunity to decrease CO2 emissions and costs. The behavior of building occupants plays asignificant role in the process of improving this efficiency both for new and existing buildings. Therefore, weintroduce a suite of web-based software applications that aim to encourage energy-efficient building occupantbehavior in an office environment under the Living Lab Energy Campus (LLEC) initiative, using the campus ofForschungszentrum J¨ ulich as a demonstration. The suite of applications, developed via a co-design process,provides means to view energy consumption data at various levels of aggregation, and to receive real-timerecommendations and incentives for behavior change. Through the Energy Dashboard, users can monitor andanalyze heating, cooling, and electrical energy consumption at building level. Leveraging IoT-enabled sensorsand actuators, JuControl offers an interface to view room-specific indoor environmental, heating and ventilationdata, and allows occupants to control the room heating by specifying a personal temperature setpoint range.Occupants also receive real-time feedback via recommendations for energy efficiency improvement, alongsideperiodic behavior evaluation in the form of ratings. The serious game JuPower gives users the opportunityto compete in teams to design a CO2-minimal alternative virtual energy system for the campus, whilst theusers’ real-world energy-related behavior is translated into in-game effects, thereby providing incentives forenergy-efficient behavior via game rewards and social interaction