The Slovenian cadastre is transitioning from 2D to 3D to better manage real properties. The demand for 3D cadastre is increasing globally, especially in urban areas. Slovenia introduced the building cadastre in 2000 to address this need. The current cadastral system is not enough for all 3D situations. Upgrading data models of the land and building cadastres will help create a unique 3D real property cadastre in Slovenia. Existing data will be useful, but additional data is required for accurate 3D representation.