This study examines opportunities for the emergence of SME networks regarding highly energy-efficient housing, as well as the barriers they face. A theoretical innovation diffusion model is developed from the point-of-view of social and environmental entrepreneurship and sustainable consumption. The qualitative analysis reflects key elements from the theoretical model and is based on a representative case study of a successful passive house network located in the Belgian Flemish Region. Data were gathered during the emergence of the network, by means of participant observation and action-based (thematic innovation) research. Interviews provided further supplementary information. The study concludes that the successful emergence of an SME network regarding highly energy-efficient housing requires a holistic approach, in which both enterprises and clients are guided in each step of the innovation-decision process. In their role as intermediaries between clients and firms, change agents should be supported by policy that facilitates networks for innovation diffusion.