3D Underground Property Rights of Transportation Infrastructures: Case Study of Piraeus Metro Station, Greece

Abstract

Underground development covers a wide range of underground uses, transportation and infrastructures networks; water and energy storage facilities; municipal spaces, housing, business and manufacturing facilities; and overall exploitation of Urban Underground Space (UUS). According to the Greek legal framework on properties underground, transportation networks, such as the metro, are developed deep enough that no compensation is due to surface parcel owners, which are usually a public entity. The current Greek cadastral system is two-dimensional and there are no records for underground transportation networks. As the need for the exploitation of UUS is arising, especially in densely populated Greek cities, such as Athens, the detailed documentation of transportation networks 3D underground property rights is essential. Herein is presented the technical and legal definition of the 3D underground property rights of the Piraeus Metro Station that is constructed in Piraeus Municipality UUS. Three-dimensional underground models for both Piraeus Station and official cadastral parcels are created so as to identify their 3D spatial intersection. For the identification of their legal and spatial status in 2D, the UUS was subdivided into layers in respect to the station’s vertical infrastructure and then correlated to the current cadastral 2D spatial data. The presented 3D underground property rights of Greece’s major urban underground transportation network facilitates its registration in the current 2D Greek cadastral system and contributes to the better understanding and the identification of legal and technical aspects of UUS rights in Greece.