There is a need for high quality, reliable and up-to-date database management systems to determine sustainable property management policies in smart cities. The database management systems capable of storing 2D and 3D spatial information can be effectively used in smart city applications related to many data themes such as buildings, cadastre, transport, land use, etc., considering the needs of applications including property valuation. The property valuation process involves an impartial assessment of the various elements that influence the potential value of a property that is not only rights, restrictions, responsibilities (RRRs), condition of real estate, spatial planning status and constraints but also environmental, geographical, location and socio-cultural information. While traditional cadastral systems provide legal information about properties with 2D geometric information, 3D building and dwelling models can provide more meaningful data for GIS analysis that can be used to increase the accuracy of real estate valuations. If a country has an effective National Spatial Data Infrastructure (SDI) with 3D support, it can be used to link different data themes, such as buildings, cadastre, land use, addresses, etc., that are required in valuation processes. However, to meet today's 3D real estate valuation needs, an extension to NSDI may be required for property valuation registers. ISO/DIS 19152-4 Valuation information specifies the characteristics and semantics of valuation registers maintained by public authorities. It covers all administrative valuations and all input and output data within the valuation processes.

The purpose of this study is to extend the NSDI of Türkiye with ISO 19152-4 Valuation information and local value affecting factors to cover all the characteristics required in the 3D real estate valuation, and to implement the developed data model. The developed data model is tested using real 3D dwelling data, and data (value affecting factors) collected through a questionnaire. The scores of each 3D condominium unit are calculated based on the questionnaire answered by the valuation experts.@en