This presentation explores how municipal data from the City of Vienna can be used to support urban analysis, urban planning, and decision-making. Using examples from current research projects, the presentation demonstrates how spatial data, 3D city models, GIS workflows, and machine learning methods can be combined to examine topics such as the 3D visualization of alternatives of zoning plans and land-use plans, the potential for attic or rooftop extensions, quality of life, and urban material stocks in the context of circular construction.