The Energy Line Extension Act (Energieleitungsausbaugesetz, EnLAG) plays a special role within the measures taken by the legislator to accelerate the network expansion as a part of the energy transition. This applies on the one hand because section 1 (2) of the EnLAG establishes by law the urgent need to expand certain projects in the area of high-voltage networks. On the other hand, this applies because section 2 (2) of the EnLAG gives the planning approval authority the opportunity to require underground cabling of extra-high voltage lines for certain pilot routes. This is possible in the case of shortfalls in the distance to residential buildings and “on technically and economically efficient sections”. In particular with a view to administrative court legal protection, there is a need for clarification with regard to the content of this phrase (see II) as well as with regard to its function and localisation within the norm structure (see III).