Yes, such a thing exists. According to experience, no one adheres to it. Within this area to be kept clear, I have: the MSH installation Gas meter Water meter Telekom box The municipal utilities did not prevent me from getting the connection laid this week and having a meter installed. I wouldn't have any major concerns about the house connection box either. What could happen there? If a fuse blows, you just have to clear the area; the "operational" fuse is in the distribution box. What I would absolutely not block or obstruct, however, is the inverter, because it needs ventilation.