The adoption of digital innovations in construction is a topic with growing importance, as organisations restructure to adopt and sustain innovations. Building Information Modelling (BIM) is currently at the forefront of this digital shift in Architecture, Engineering, and Construction (AEC) industry. The relation between knowledge sharing and sustained innovation adoption in organisations has been previously acknowledged by management scholars. There is further room to adopt a structurational view of knowledge and focus on how agency contributes to knowledge sharing for increasing digital innovation adoption in firms. This paper uses the theoretical lens of boundaries and boundary brokers to guide the data selection and interpret a rich dataset about boundary brokers of digital innovation. The research aim is to explore how these boundary brokers, referred to as digital innovation champions, facilitate knowledge of digital innovations and BIM to support digital transformation in firms. A single case study of a large international multi-disciplinary consultancy was used as a research setting. Data were collected through interviews with the digital champions as well as with additional data collected from the internal online platform for data triangulation and research validation. Key findings include the multi-faceted levels of boundaries crossed by the digital champions to share knowledge about digital innovation: hierarchical, professional and organisational boundaries. Namely, the digital champions were found to hold multiple memberships in groups, holding both technical and inter-personal competences as well as engaging in conflict resolution. The study concludes with implications for practice and suggests courses of actions to increase knowledge sharing in firms for innovation adoption by developing and incentivising individuals.