Beschreibung:
<p>The current cadastral systems are usually based on a 2D parcel maps and land registries having references to different documents. In many countries, the parcel maps, as well as the registries and referenced documents, are represented digitally. The 3D cadastral systems have usually a similar approach, where the descriptions of the 3D components are represented by drawings in PDF format. This article focuses on creating the 3D geometries corresponding to 3D property based on existing 3D building models. The article investigates shortages of IFC and CityGML, the most prominent semantic building models for representation of BIM and geospatial models respectively, as well as a unified building model (UBM) that was developed earlier for modelling complete and real 3D cadastre information system. The result shows that IFC, CityGML, nor the UBM has capabilities for such tasks. The article proposes an extension to the UBM in adding different subtypes to the boundary surfaces above and underground. The extended UBM is then implemented in a case study of a hospital building in Sweden. The implementation shows that by adding the four subtypes “Building Elements Surfaces,” “Digging Surfaces,” “Protecting Area Surfaces,” and “Real Estate Boundary Surfaces” of boundary surfaces, it has become possible to model all the needed surfaces that define 3D cadastral information of a building.</p>