Each federal state can set its own distance rules for heat pumps. In Hamburg, the distance between building-like structures and neighbours must be 2.50 metres, while in Berlin or Schleswig-Holstein it must be three metres.
In Bavaria, the Higher Regional Court classified heat pumps as not building- like, and an appeal to the Federal Court of Justice is underway. In Germany, we have the situation that we do not have one building code, but 16 state building codes. To circumvent this, builders can have installers confirm that the heat pump complies with all regulations.