Towards a CityGML 3D Property Valuation Model based on BIM

3D variables have a substantial influence on the property value. In the same building, property units are exposed differently to environmental conditions, such as: sunlight exposure, air quality etc. and each unit is made up of a variety and complex attributes (materials, cost, energy efficiency etc.). These parameters are some of the main 3D variables impacting the property value. Therefore, a number of studies has been carried out recently to introduce 3D modeling techniques and 3D data sources in order to improve the assessment of property units’ value. These studies include the recent achievement regarding the International Valuation Information Model, an extension of the ISO 19152:2012 Land Administration Domain Model (LADM). It is developed for immovable property taxation to serve valuation practices in administration authorities. It provides also information related to physical property units’ characteristics, locational and some environmental characteristics. The physical variables are mainly derived from the 3D cadastral model while 3D locational and environmental variables are derived from 3D spatial datasets. These variables are integrated into the LADM-Valuation Information Model. However, this model approaches the property valuation on a 3D cadastral and 3D legal viewpoint, we choose to address the problem in a different perspective, considering that a property value can be defined by its indoors variables Building Information Model (BIM) and outdoors variables specified from the CityGML 3D geospatial standard. To tackle this approach, the first outline of our research is to examine how to select the significant 3D variables for property valuation and to identify the relevant 3D data sources required to construct the property valuation model for the indoors (BIM) and outdoors (CityGML). The expected outcome of this research is to develop a generic property valuation model to support real estate valuers, contractors, developers and administrations. The proposed approach can be meaningful to the existing International Valuation Information Model. It may be considered for the future investigation for integrating 3D variables that impact property valuation.