Apologies in advance for reviving an old thread, but it seemed pointless to start a new one.
We looked at a house that we loved and the problem was not so much the proximity to the lines but the view of them from the kitchen window in particular.
We did some additional research, contacted the relevant authorities to get a precise measurement, but at the end of the day it comes down to not just whether you can see them but do you hear them clicking/buzzing. This can vary depending on the weather. Mostly what we hear is the birds chirping. Tons of birds sit on the wires.
So then we found another property, no power lines nearby but it says the following in the "grundbuchauszug" (official property deed)
Baurecht für eine Niederspannungs Kabelkabine mit Kabeldurchleitungsrecht zG der AEW Energie AG, bis 13.08.2054 
The house is for sale by the owners and an agency. It was the agency that forwarded the document to us. The owners have prepared a very detailed documentation but no mention of this "right".
Is this a house to walk away from?