Eco-feedback has been demonstrated as an effective strategy to promote energy-saving behavior among occupants in buildings by providing real-time or historical information on energy consumption and environmental impacts. However, the application of eco-feedback in academic buildings for space choices is limited. In this study, we explored the impact of providing eco-feedback on occupants’ space choices in university Activity-Based Workspaces (ABW), where individuals select their workspaces using an online booking system. We designed two user interfaces: one baseline interface with no eco-feedback, and also an intervention interface that included eco-feedback. A within-subject user interface evaluation study was conducted, and the results suggest that eco-feedback significantly motivates occupants to select highly eco-friendly spaces ( p-value < .05). Consequently, providing eco-feedback in university ABW environments can encourage more eco-friendly and sustainable decision making and has the potential to reduce the contribution of buildings in energy-related carbon emissions.