Strengthening capacity for cross-sectoral coordination has a crucial role in enabling ambitious climate mitigation. This research work integrates the Sustainable Development of Energy, Water and Environment Systems Index into a policy framework with three main components to compare possibilities for improving urban system performance. Tiers of integration are defined and compared with the index results for more transformative action. The levels range from unintegrated urban sectors and emerging integration, including those with urban land use and spatial planning, to advanced integration across the urban system. The case study is based on a municipality that is benchmarked to receive an index score of 27.783, placing the urban area in rank 79 among 120 other cities. The measures in the existing action plan are compared with opportunities that would support the municipality in reaching higher tiers of urban integration in the future. Policy learning from other urban areas to which the index is applied is foreseen to support collective action in addressing synergistic opportunities for mitigation. The results have implications on considering urban system integration in the transition to net-zero targets, missions for climate-neutral cities, and the realization of 100% renewable energy systems. (c) 2021 Published by Elsevier Ltd.