In this article, it is argued that processes of co-production can support teachers and students in organizing resources for justice through science learning. Drawing upon a critical justice conceptual framework, critical ethnographic data from one urban middle school classroom during a unit focused on engineering for sustainable communities were analyzed. Findings describe how processes of co-production yielded new Discourse threads focused on sustainability, whose ideas matter, and empathy, which were embodied in students' engineered artifacts and how students talked about using those artifacts. Such embodiment positioned students as rightfully present and powerful experts in science and engineering. We discuss how processes of co-production supported justice by supporting new social relationships between the teacher and students that helped to make space for collective engagement of students' political struggles against the oppressive practices of schooling as an integral part of science learning.