Johann Hafellner studied at the Graz University of Technology and completed his master's degree in civil engineering. His dissertation dealt with the hygrothermal behavior of building component connections in contact with the ground with interior insulation in Wilhelminian Style houses. Johann Hafellner is an assistant professor at the Graz University of Technology (Austria) at the Institute of Building Physics, Services and Construction IBPSC. He is active in teaching at the undergraduate and graduate levels in building construction. His research focuses on structural details in the context of building physics and legal requirements, sustainable building design, building design of existing buildings and optimization of construction methods and procedures.