During the planning stage of major projects such as the construction of motorways or the power line planning it is often foreseeable that their realization requires an expropriation . Numerous legal regulations give such planning decisions "enteignungsrechtliche Vorwirkung" (pre-effects concerning the expropriation). This study traces the development of this legal concept on the basis of these regulations and the jurisdiction of the constitutional and administrative courts, comments on the constitutional dogmatic classification of the legal concept and distinguishes it from other legal institutions. Concentrating on planning approval decisions, the prerequisites for measures with "enteignungsrechtlicher Vorwirkung", the boundaries of legal protection for people who are affected by this effect and the composition of this group of persons are delineated and the plan-ning is differentiated from the expropriation process. In this way, an overall picture of this legal concept is designed and evaluated.