The railway infrastructure building Sedrun is located in the portal area of the access tunnel Sedrun, which is required for the safe operation of the 57 km long Gotthard-Base-Tunnel. It is a two-storied solid structure. The south and east sides of the around 40 m long, 15.5 m wide and 10 m high building are of exposed concrete. The other two facades are composed of metal, which allows for ventilation, while on the east side several uniformly arranged windows are installed. The flat roof is extensively greened. The shell construction works include the overall technical installations for the ventilation- and heat regulation system, energy supply, installation of doors, gates, railings, as well as sanitary installations, paintworks and installation of technical fire protection facilities. All spaces are equipped with double floors and two crane systems for mounting and maintenance works. The main purpose of the building is the accommodation of the railway infrastructure facilities, to ensure the safe operation of the tunnel. Next to the entire command-, communication- and supply installations, there are also a large diesel emergency power system for each tunnel tube as well as a transformer in this building.