"In geographic information systems (GIS) the collection, combination, analysis and visualization of spatial data is carried out in digital maps. Due to the significance of the location for this spatial data basis a commercial use of GIS seems to be suitable for the real estate economy. In German practice however, this is only true for isolated, heterogeneous and little transparent individual applications. The practical problems today result less from technology, but rather arise from the data obtaining and availability. For this reason the possible use of GIS applications is evaluated on the basis of existing empirical analyses of the value relevance of spatial data parameters for real estate decisions. Applications, target groups and requirements of property-related GIS are developed thereupon systematically following the value-added chain in the life cycle of real estate. Decision makers only will use and pay for property-related GIS, if the specific application solutions generate an ""added value"" for them. Based on this central assumption, the range of application extends from value inquiries in the context of financing and portfolio decisions in the letting phases of real estate to the use in location and market analysis in the developmental stages of real estate. The latter is shown exemplarily with the modeling of an GIS to forecast the supply and demand of office property areas."