Understanding student interaction in learning spaces is an ongoing challenge. The move away from didactic lecture delivery towards more active and hybrid learning renders this challenge ever more difficult. Researching pedagogic use of informal learning space, which is not formally timetabled or controlled, is always challenging because it is interacted with only transiently by both students and teachers. This paper introduces a mixed methods, phenomenological approach used in recent research to investigate campus learning spaces in face-to-face learning contexts. The full mixed methods approach combined space occupancy monitoring data with naturalistic ethnographic observation, field interviews and, where appropriate, more formal in-depth interviews to provide an effective way of understanding student and teacher engagement with learning spaces. Convergent use of these qualitative and quantitative methods yielded data which informed the application of subsequent methods, and the investment of researcher, pedagogic and infrastructural resource. In this paper we argue that as learning outside of formal teaching spaces increases, these mixed methods enable better, more efficient monitoring of pedagogic use of informal learning spaces. The mixed method can be adapted depending on the question being addressed and has the potential to inform resource allocation and investment into pedagogic and infrastructural change.