WTM Engineers has been in charge of Hamburg's 275-meter television tower since its inception in 1965, and has conducted structural inspections of both the 1965–68 construction and the early 1980s modifications. In the early 2000s, after more than 40 years of use, the tower required modifications, inspections and repairs. Extensive as-built inspections formed the basis of the repair design, using specialized mobile scaffolding and enclosures. In 2001, the restaurant and viewing platforms at a height of approximately 140 meters were closed and have not been reopened since.

In 2015, WTM Engineers carried out a feasibility study, which included an evacuation concept for the public levels, necessary reconstruction measures and a rough study for the construction of a new entrance building.

After more than 20 years, the Heinrich Hertz Tower is to be reopened to the public. On levels 13 and 14, a combination of observation deck, restaurant and event space will be created, as well as a new entrance building at the foot of the tower. This will be accompanied by the planning of fire safety upgrades to the public areas, including the access route in the shaft.