This is a publisher's version of a paper presented at the 2nd International Workshop on 3D Cadastres, Delft, The Netherlands, 16-18 November, 2011 published by FIG. http://3dcadastres2011.nl/papers/ ; Current cadastral data models use a 2D land-parcel definition and extend it to cover 3D requirements. This approach cannot adequately manage and represent the spatial extent of 3D land rights, restrictions and responsibilities (3D RRRs). This paper aims to develop a 3D Cadastral Data Model (3DCDM) to configure 3D cadastral frameworks, manage and represent 3D RRRs, and facilitate 3D cadastre implementation. Three underlying principles have been proposed to develop the 3D Cadastral Data Model (3DCDM). These principles are: • Principle 1: The 2D cadastral data model is a sub-set of the 3D cadastral data model, • Principle 2: The 3D cadastral data model should not only accommodate 3D RRRs and their association with physical objects: the data model should also represent the spatial extent of 3D RRRs, and; • Principle 3: The 3D cadastre data model should cater for a broad range of land administration functions including land tenure, land value, land use, and land development with sufficient detail. These principles are used to assess and modify the core cadastral data model. Additionally, principles related to the legal property object are also used to modify the 3DCDM. The legal property object combines interests and its spatial dimension into a single entity. This creates more flexibility and enables inclusion of complex commodities and all kinds of RRRs. The first version of a 3D Cadastral Data Model (3CDM_Version 1.0) is provided at the end of this paper. 3DCDM maintains both legal and physical parts of 3D objects. The data model has wider application than the traditional requirements of cadastral systems: it is also usable in applications such as urban planning and disaster management. ; 16-18 November, 2011