`titrebEnergy design in urban development projects, between learning process and negotiations. Insights from Bordeaux, France`/titreb`np pagenum="174"/bThe raise of public policies oriented towards energy transition puts increasing pressure on urban development projects, which are more and more supposed to demonstrate exemplarity in energy management. Analyzing the way energy transition is processed into matter then requires a better understanding of how such pressures are translated into the projects’ technical design processes. Drawing on the design of energy requirements in one project, we show that the analysis of such processes needs to account both for learning dynamics that build the cognitive framework upon which the actors rely, and for power relations that drive and focus these dynamics. By doing so, we contribute to building a body of knowledge on systems of collective action that embody energy transition into the material fabric of cities and urban energy systems.