The BauSIM Conference has been organized under the auspices of IBPSA Germany and Austria since 2006 on a biennial basis. The conference focuses on building and district simulation and associated methodologies. Emphasis is also placed on topics such as building information modelling (BIM), building component simulation, and the monitoring and operation of buildings and urban systems. The BauSIM 2020 proceedings present current research results and trends in the field of simulation and the data-based design of sustainable buildings and communities.