The energy companies Uniper and Eon are planning drastic measures to save energy in the coming winter.
Uniper will "hibernate" around half of its office space in the Düsseldorf group headquarters from the beginning of November, a company spokesman said on Monday.
These rooms should then no longer be used and only heated to 14 degrees.
All electrical devices in the affected parts of the building would be shut down.
The employees would be distributed to the remaining rooms, Uniper reported.
This is possible without any major problems because the 2,500 employees of the group in Düsseldorf no longer have permanent jobs anyway, but reserve a desk in a booking system if required.
In this way, Uniper hopes to be able to reduce energy consumption by at least 25 percent.
The "Rheinische Post" had previously reported on the group's plans.
Eon also announced that it intends to shut down entire parts of the building for the entire heating period by mid-April.
"The employees in different areas therefore moved together at the beginning of October or will do so shortly," the company announced.
The affected rooms should only be heated in such a way that the building and the infrastructure are not damaged.
Eon's goal is to reduce the energy consumption of its own buildings by at least 20 percent on average, the group emphasized.
In addition, all light sources that are not absolutely necessary, such as logos and outdoor lighting, would be reduced or switched off completely.