AD> Preisträgerin des Nachwuchsförderpreis des Vereins Frauen in der Immobilienwirtschaft e. V. 2013 This empirical investigation is directed towards the uncertainties in the prediction and evaluation of operating and repair costs that exist in current real estate management practice and make a sustainable provision of real estate difficult. The decisive causes of measured differences in the outlay for operating and repair measures are determined by means of descriptive and inferential statistics on the basis of sample data obtained from 130 public schools of the state capital Stuttgart, Germany, comprising around 300 school buildings and 140 sports facilities. This analysis also includes the definition of the appropriate building reference areas for an adequate normalization of the consumption and cost data concerned. Numerous distributions of total consumptions and costs as well as their respective indicators are presented for various cost types and influential determinants in order to provide reliable reference values for valid cost predictions and comparisons. In addition, the practical application fields of the research findings are demonstrated in detail by means of different examples for early planning stages and benchmarking purposes.