The transition of the energy system towards decentralized renewable energy sources poses both opportunities and challenges for quarters, districts, and municipalities. To aid local authorities and policy makers in navigating this complex topic, we present a decision-support and pathway recommendations tool. The tool is preloaded with publicly available data and offers modeled data for missing aspects to both display the status quo and enable an assessment of different options in future scenarios. These scenarios include the replacement of fossil heating systems with heat pumps and district heating networks, the retrofitting of the building park, the exploitation of the potentials of renewable energies like solar photovoltaics, wind and biomass as well as the implementation of thermal energy storages and batteries. The simulation is performed using a Python-based model with integrated optimization using the mixed-integer linear programming framework Calliope. This tool will help community representatives, policymakers, and energy planners to support the integration of renewable energy into the communal energy systems and thereby help to reach the European and Swiss emission targets.