The Department Civil Construction (BAU) is responsible for the planning, construction, and maintenance of the entire building infrastructure on campus. It initiates and develops projects and measures based on the requirements of the Campus Master Plan and the GSI renovation register, thereby ensuring that needs are met and that building regulations and legal requirements are complied with.

In the area of building maintenance, BAU is responsible for the repair and maintenance of buildings and safety systems as well as providing technical support for the experiment buildings. It thus directly supports the scientific and accelerator operations as a service provider in an advisory and constructional capacity. In the area of construction logistics, it coordinates construction measures and the corresponding site areas as well as the logistics requirements for the entire operation of the campus.