Purpose: The purpose of this paper is to demonstrate the relevance and use of the concept "reverse salient" in ambitious infrastructural change. Thomas Hughes, in his seminal study of socio-technical system building, observed that the elimination of "reverse salients", i.e. subsystems that because of their limited performance hold back further development, was a central driver for creativity and innovation. It is argued that in sustainable infrastructural transformations, however, reverse salients that resist change are more often neglected than addressed. Design/methodology/approach: Higher education institution campuses combine laboratory-like conditions and sufficient internal complexity to be used as test-beds for ambitious sustainable change in the built environment. In this article, a neglected barrier to the transformation of a small campus into a zero emission campus is revealed, described and addressed. Findings: In terms of substantive findings, first, it is demonstrated how parts of infrastructures that -- often for good reasons -- have been neglected in efforts to reduce climate impacts can be identified with the help of a historical exploration of the site and through close collaboration with local facilities managers. Second, a temporary low-tech intervention is presented that addressed the critical problems related to these "reverse salients". Research limitations/implications: The limitations of a case study approach apply to this study. Particular caution has to be exercised in terms of generalisation. Moreover, the intervention would benefit greatly from stricter control and additional iterations of the intervention which have not yet been performed. Practical implications: In addition to technology-focussed, top-down initiatives, which often struggle with actually reaching their ambitious goals in routine operation, neglected parts of campuses can contribute greatly to energy and emissions reductions. Moreover, it is demonstrated that and how local technical personnel has an important part to play in infrastructural transformations. Originality/value: Concepts developed in the study of socio-technical system building have not yet been applied in the study and practice of sustainable infrastructural transformation. Their contribution is demonstrated. Moreover, living labs are notoriously difficult to evaluate. In this case study, processes and effects of an innovative living lab intervention are described and analysed. This enables a better understanding of restrictions and possibilities of experimenting in real-life settings.