Cross-sectoral transition work at the heart of the regime: Transforming incumbent systems in utility infrastructure planning in Amsterdam

• Sustainability transitions are increasingly addressed by regime actors. • These actors can leverage regime proximity but face significant systemic barriers. • To examine system transformation, we study a cross-sectoral case in Amsterdam. • As transdisciplinary action researchers we engaged in the transformation process. • We identify three strategies for regime-actors in cross-sectoral transition work. Regime actors pursuing sustainability transitions face a key challenge: how to leverage their proximity to the regime while navigating its constraints? This article examines a cross-sectoral transition programme in Amsterdam, involving the municipality, a water company, and an energy grid operator. Drawing on transition work, practice theory, and our transdisciplinary engagement in the programme, we trace how these actors collaborate and attempt to overcome institutional barriers from within. We identify three strategies for regime-embedded actors engaged in ‘cross-sectoral transition work’: (i) combining the development of novel reflexive practices with engagement in established practices, (ii) bridging operational and strategic levels through 'intermediary work', and (iii) pursuing 'essential wins’ - relatively small, but necessary institutional changes that align short-term action with long-term system innovation. Together, these strategies broaden the analytical scope of transition work across horizontal, vertical and temporal dimensions, and advance understanding of cross-sectoral transition work from an embedded position.