This thesis discusses the current status of geographical information systems in the context of property valuation as well as possible fields of use for web-based systems. To achieve this, an analysis of 25 property appraisals was conducted to review the current use of geographical information systems in the process of property valuation. Furthermore, a quantitative survey aiming at experts and employees in this field, was performed. Based on the results of this analysises, also by taking into account available literature, possible use cases for web based geographical information systems are discussed. Finally, an example application is constructed with the goal of demonstrating how these systems might be used in the context of property valuation.