Abstract In order to combat climate change and reduce carbon dioxide emissions as suggested by the Intergovernmental Panel on Climate Change (IPCC), the contemplation of different knowledge types is discussed as a leverage point for transforming towards sustainability. In order to analyse how a science-practice dialogue can improve the understanding of transformation processes towards low-carbon societies, we set up a dialogue process in North Rhine-Westphalia to envision a low-carbon future. We addressed the deficits of previous transdisciplinary projects and tested different dialogue formats. The approach applied put us scientists in the unusual position as facilitators of dialogue. This contained some challenges but also offered an in-depth understanding of the science-practice dialogue that would not been possible with traditional scientific methods. The participating stakeholder perceived bringing together different actors with complementary knowledge and experience and associated mutual learning as beneficial. However, the wish not only to gain knowledge but to influence decision making determines whether a dialogue process is perceived as effective. We found that envisioning processes are valuable to explore highly uncertain future processes. In addition, the envisioning workshop revealed the actual source of conflicts and thus, creates an effective dialogue by addressing the actual differences and not the symptoms.