The planning support system URBio is demonstrated via two case studies. Both case studies are located in the canton of Geneva. The first case study is a greenfield planning project, where the goal is to build a new district on former agricultural land. The project responds to the urgent, global challenges of urbanization, and climate change by developing a relatively dense, ecofriendly district. The second case study focuses on a brownfield planning project, that is, the redevelopment of an existing neighborhood. Consequently, the planning support system was adapted to address the challenges and measures specific to urban redevelopment. Through both case studies, the reader will be walked through a typical application process of URBio, illustrating how it is used interactively to explore and narrow the search space, how new questions might come up during this process, and how URBio enables to find further answers. The first case study will illustrate with practical examples the trade-offs between common planning targets such as energy, density, and social aspects (e.g., share of parks). The second case study provides a more in-depth analysis of the current state of the energy system, the limits in achievable densities, and emission saving potentials by replacement of conversion systems and thermal building refurbishments.