The article discusses how European principles for regional development have influenced planning in the Grenoble and Geneva city regions. By analyzing planning documents and conducting fieldwork, the study shows how these principles have led to changes in governance and planning practices. Both regions have experienced urban growth and sprawl, leading to the incorporation of urban, peri-urban, and rural areas into planning territories. Strategic projects based on multi-level governance processes have been implemented to address these challenges. The comparison between Grenoble and Geneva highlights differences in governance, decision-making processes, and impacts on spatial development. Residential development issues like segregation and land consumption are now integrated into broader urban development strategies, with their success depending on effective multi-level city region governance.