In this article we focus on the co-creation of ideas. Through the use of concepts from collaborative learning and communication theory we suggest a model that will enable the cooperative nature of creative design tasks to emerge. Four objectives of the model are stated and elaborated on in the paper: that the model should be anchored in previous research; that it should allow for collaborative aspects of creative design to be accounted for; that it should address the mechanisms by which new ideas are generated, embraced and cultivated during actual design; and that it should have a firm theoretical grounding. The model is also exemplified by two test sessions where two student pairs perform a time-constrained design task. We hope that the model can play a role both as an educational tool to be used by students and a teacher in design education, but primarily as a model to analyse students' cooperative idea generation in conceptual design.