This presentation introduces the development of a practical QGIS plugin designed to support urban structure evaluation by municipal staff. In many Japanese municipalities, computing and interpreting urban structure evaluation indicators still depends heavily on external consultants, as the work requires specialized GIS skills and the integration of diverse datasets. Developed under Japan’s Project PLATEAU, the plugin supports workflows for using 3D city models and related public datasets to calculate indicators and visualize results through maps and charts within QGIS. The tool was evaluated through pilot workshops and interviews with municipal staff from multiple municipalities in Japan. The presentation will cover the background of the project, the functions and intended use of the plugin, findings from pilot workshops with municipal staff, and lessons learned from developing an open-source geospatial tool intended for municipal practice.