Two dimensional (2D) Land Administration Systems (LASs) do not adequately represent 3D underground objects. It is not easy to identify the owners of these objects and the relations between objects below and above the surface are not explicitly provided. A 3D LAS can however facilitate a better understanding, as well as a more efficient registration and clear visualisation of the Rights, Restrictions and Responsibilities (RRRs) of the 3D underground objects. To represent 3D underground objects, BIM/IFC (ISO 16739:2018) models can be used from design. The LADM (ISO 19152:2012) standard should be used to provide a formal language to register spatial and non-spatial information in LASs. In this paper a literature review is performed to develop a standardised workflow to model the legal spaces of BIM/IFC models of 3D underground objects according to the LADM in 3D LASs. With this workflow the user is provided with a general framework, where adherence to the BIM/IFC and LADM standards enhances interoperability, increases efficiency and reduces costs. More research needs to be done on validating the workflow with use cases.