In this article we present a case study of our experiences of using existing IoT infrastructure to create a campus scale “living laboratory” for promoting energy savings and environmental sustainability. As a series of lessons for others creating IoT systems from existing city infrastructures we offer the challenges we have experienced through our attempt to join up and re-purpose existing energy monitoring and building management systems as an IoT infrastructure for a “smart campus”. We highlight the limitations of particular views of a campus from a purely data-driven perspective, advocating data- aware over data-driven approaches that engage with a wide variety of stakeholders. Finally, we reflect on the inclusion of people’s practices in understanding and designing smart cities, repurposing existing IoT, more careful consideration of ethics and domestication when co-creating smart campuses and the importance of challenging the existing rhetoric around energy waste in Smart Cities and Smart buildings research.