Layer approach to ownership in 3D cadastre in the case of underground tunnels

•3D cadastre for subway is a challenge for national land administrations systems.•3D cadastre for subway improves secure of constructing, financing and managing.•3D cadastre for subway improves information for future underground development.•3D cadastre allows for legal separation of the subway tunnel from ground property. The paper focuses on approaches to the registration of real property rights in the case of underground or subway tunnels in different EU countries: Austria, Bulgaria, Czech Republic, Croatia, Greece, Poland, Slovenia, and Sweden. The authors conducted analysis on the registration of rights to subway tunnels in the chosen countries, including its effectiveness in ensuring appropriate property rights to construct and exploit tunnels. Special attention was given to limitations related to the lack of legal provisions vertically dividing space, i.e. into layers, and referring to the ownership right to the layers. Benefits which might be achieved by the introduction of a 3D real property subdivision were pointed out. The analysis of the available data concerning the geometry of subway tunnels in particular countries was presented. The authors tried to answer the question whether the accessible data concerning the geometry of subway tunnels allows to generate a 3D geospatial model of a constructed object, and to specify the space which should be determined as a 3D parcel in the 3D real property cadastre, for the purpose of registering property rights for the object (the tunnel).