3D Data for Better Property Value Estimation in the context of LADM Valuation Information Model

Abstract

Property valuation is a process of estimating value of an immovable property. The legal, geometric, physical and environmental characteristics of the immovable property together with the economic indicators are taken into consideration during this process. Traditional cadastral systems only provide two-dimensional (2D) legal and geometric information about property units. However, today’s complex valuation practices (e.g. computer aided mass appraisal) would benefit significantly from three dimensional (3D) information on not only property units but also their physical counterparts (e.g. buildings, building parts). Moreover, 2D and 3D environmental information is needed for determining environmental conditions about immovable properties to better estimate the values of them. A collaborative research initiative has proposed an international valuation information model that extends the LADM for specifying semantics of valuation registries maintained by public authorities. The current version of the LADM Valuation Information Model, however, does not include detailed specification for the environmental characteristics of immovable properties (e.g. presence of views, level of visibility and distance to amenities) which can be derived with 2D and 3D geospatial analyses by means of various data sources. The purpose of this paper is to examine which geospatial analyses, especially 3D analyses, can be used to provide information about immovable properties including environmental and locational characteristics for property valuation activities. Furthermore, it is investigated that how property valuation can benefit from data sources including semantically rich 3D building, city and cadastral models for deriving environmental and locational characteristics of property units. To achieve these objectives, the data sources and geospatial analyses are initially investigated in the context of property valuation. Then, the paper focuses more on viewshed analysis. By using open topography, building and height datasets of the Netherlands and 3D GIS analysis, a viewshed analysis is presented to show how it can be utilized using different data sources for better understanding and explanation of values of the properties. The paper is concluded with a discussion to what extent it is possible and meaningful to include (derived) environmental characteristics of properties in the LADM Valuation Information Model