Research institutions meet increasing demands for transparency, accountability, added value and reuse of all aspects of scientific production, from documenting the research process to sharing underlying data to open access to publications. Going beyond admirable slogans about openness there is a clear need for support infrastructures relating to the actual practice of Open Science describing metadata, archiving datasets and publications and disseminating increasingly interdisciplinary research results. Research libraries, having always been stewards of research institutions’ collective knowledge and offering a variety of research support services, are in a unique position to offer future support for Open Science based on the core competencies already existing at the library. This paper describes the process of building a comprehensive research support structure for Open Science at the university library of the Norwegian University of Science and Technology. It shows how the library identified stated, but not necessarily operationalized, university strategies for Open Access and Open Data, and proceeded to strengthen its existing competencies in this area with human resources and a targeted approach to linking the library to the central research infrastructure of the university. This resulted in the library assuming responsibility for new research support services and plans of action for Open Access and Open Data for the whole of NTNU.