To address climate emergency, many countries are tightening their energy efficiency targets. How this ambition can be realized is still an open question. One thread of research focusses on intermediaries, i.e. actors contributing to transition processes by facilitating and enhancing the actions of others. This paper presents a participatory research project exploring the intermediation functions fulfilled by a regional energy efficiency programme. Intermediation functions are interpreted as the outcomes of the tasks performed along the lifecycle of programme activities, depending on the pursued intents. Based on a series of strategy workshops, five successive task categories are identified: (a) design, (b) communicate, (c) operate, (d) coordinate, and (e) strategize; along with three intent levels: (i) support, (ii) connect, and (iii) mobilize stakeholders. These are articulated as a ‘‘tasks-intents space’’ where activities evolve. Typically, while programme activities were primarily operated to support implementation of energy efficiency measures, work at the design stage nevertheless included connecting early adopters, and managers were expected to ultimately raise to a more strategist role, enhancing the mobilization of potential beneficiaries. Two factors are found to determine this focus on the support to individual measures: (1) the imperative to report quantified energy savings, and (2) the compartmentalization of competencies. This leaves the tasks-intents space partly unexplored, corresponding to intermediation functions that are yet to be studied. For instance, facilitating the convergence of competing visions of change and integrating existing solutions within a coherent framework are identified as promissory paths towards achieving the required magnitude of change.