The article presents the Slovenian land administration system focusing on the cadastral registration of buildings. We present the current structure of the land administration system and the latest upgrades introduced in 2018. In addition, we outline the main changes in the near future as a result of the new legislation adopted in April 2021 that will come into force in April 2022. The ongoing research and development activities led by the Slovenian SMA (GURS) are further presented. In light of recent research, we study the possibilities for long-term developments of the Slovenian cadastral system towards a fully functional 3D cadastral system. We present two case studies related to the registration of buildings. The buildings were recently registered according to the official registration procedures currently in force. We performed additional measurements and 3D modelling required to obtain a 3D representation of the registered real property units. Once we had the 3D real property units available, we investigated the possibilities of storing the data in a spatial database. The current official registration procedure is compared with the presented procedure for obtaining 3D real property units. We conclude that the proposed approach still needs to be optimised in terms of data processing efficiency for operational introduction in the Slovenian land administration system, where each new building needs to be registered. However, it represents a viable option to enrich the registration documentation for complex RRR situations, where clear 3D spatial delineation of RRRs is needed.