What does "Sanitary pre-installation in the walls" mean

Thank you for your tips. We have now received confirmation that the [Unterputzspülkästen] are present and have inquired about the mounting of the washbasin countertop and countertop basin. Currently, threaded rods for 60 cm washbasins are apparently planned. That indeed would not have fit!

Currently, threaded rods are apparently intended for 60 cm washbasins. That indeed would not have fit!

Hiltischwinger's favorite interface is called "stone shell construction," where you really have to rethink a lot when it comes to wood stud construction (and actually already include the installation walls in the GWS trade).