Over the past decade, numerous countries and researchers have been investigating the potential of 3D cadastre based on the Building Information Model (BIM). In Türkiye, the General Directorate of Land Registry and Cadastre (GDLRC) has been engaged in the “Production of 3D City Models and Creation of 3D Cadastral Bases Project” since 2018. One of the objectives is to develop 3D (physical) digital building models (and databases) through the digitization of floor plans of architectural drawings. In order to ensure the long-term viability of this project, a new regulation was issued in 2021. This regulation mandates the submission of 3D digital building models to the land registry in order to register condominiums. The future goals of the GDLRC include utilizing the 3D digital building models produced to create legal spaces in condominium buildings for the 3D cadastre. However, no research has yet been carried out for this goal. The objective of this research is to identify the legal and BIM data requirements for deriving legal spaces in condominium buildings, in light of the legislative analysis, and to develop a web-based 3D cadastre visualization prototype (showing both legal spaces and physical objects) based on the requirements obtained from the scientific literature. The result of this research demonstrates that well-structured and annotated BIM data can be used to develop a 3D cadastre prototype that meets the legal requirements in the case of Türkiye. Moreover, it is evident that, although the GDLRC has initiated the construction of a robust foundation for a 3D cadastre based on BIM, further enhancements and resolutions must be implemented from a legal and technical standpoint. It is postulated that the identified requirements and the proposed methodology in this research may assist decision-makers in Türkiye and globally in formulating their strategic plans for a 3D cadastre.@en

The interest in using 3D data in property valuation has been increasing during the last decade. The usage of 3D data models in valuation can be basically grouped in two main categories: (a) supporting mathematical models with variables produced through 3D analyses (e.g. view) in order to better estimate the values of properties and (b) consuming 3D data models to visualise valuation units in 3D and disseminate values of properties associated with the visualised units (legal or physical space). The current paper focuses on the latter category in particular. The main purpose of this paper is to develop a prototype system utilising the proposed Valuation Information Model extension of ISO 19152 Land Administration Domain Model (LADM_VM) compliant dataset in order to create web-based, thematic valuation maps for 3D valuation units (e.g. condominium) and groups (e.g. multi-occupied building). In the first part of the paper, it is attempted to justify why an extension to the core LADM is required to represent valuation information. It is noted that LADM_VM enables to record 3D spaces of valuation units, and input and output data of 3D analyses. Therefore, LADM_VM can be used as basis for developing 3D visualisation and dissemination prototype. In the second part of the paper, special attention will be given to the 3D visualisation and dissemination of spatial, thematic and temporal characteristics of valuation information and a prototype is developed using the open datasets of the Netherlands. It is expected that the outputs of this paper will contribute to the development of local or national prototype systems for sharing valuation information effectively and efficiently. Therefore, it may be considered that the outputs of the paper not supports in increasing the communication level with public, but also supports politicians and planners in decision-making processes and helping them to understand the property market better. With the proposed system (prototype) the trust in the valuation is expected to further increase due to the high level of transparency. @en