To deal with recent reforms and the accompanying complexity of work in secondary education, ongoing collaboration between teachers has become more important. A community is seen as a promising learning environment to support and embed collaboration into the culture of the school. However, community theory for the design of teacher communities seems underdeveloped. Therefore, this study aims to formulate a set of design principles to foster the development of teacher communities in secondary education. The set of design principles is based on a review of literature, as well as on a best-practice case. The case study was used to validate design principles from the literature in the target context. The resulting design principles were based on context-intervention-mechanism-outcome logic that takes into account the context-dependency of interventions as well as the mechanisms that help with understanding of how interventions produce certain outcomes. Implications for practice relate to ownership and co-design of the arrangement. The set of design principles provides a practical basis for teachers and administrators aiming to facilitate community building in their school. Future research is recommended on testing the effectiveness of the arrangement in the target context by means of a multiple case study.