In urban planning, sophisticated simulation models are key tools to estimate future population growth for measuring the impact of planning decisions on urban developments and the environment. Simulated population projections usually result in bulky, large-scale, multivariate geospatial data sets. Millions of records have to be processed, stored, and visualized to help planners explore and analyze complex population patterns. This paper introduces a database driven framework for visualizing geospatial multivariate simulation data from UrbanSim, a software-based simulation model for the analysis and planning of urban developments. The designed framework is extendable and aims at integrating methods from information visualization and cartography into planning processes.