Besides the price, functionality and quality of office properties play a major role in the decision-making process of renting or purchasing real estate. A number of real estate based criteria have to be judged for appraising these characteristics properly. Assessment and selection of criteria differs depending on the perspective ñ is it an investor¥s or occupier¥s point of view? This paper analyses existing literature to establish a set of criteria that are relevant to the process of renting or purchasing real estate. This way, the scientific foundation for the development of an online software tool, which is designed for assessing commercial real estate, is provided. The internet based program ñ OFFICE SCORE ñ offers a standardized assessment of office properties for investors as well as for occupiers by analyzing price, quality and functionality, thus productivity issues. Due to the use of Web 2.0 features, office properties can be com pared with the overall market for office real estate while considering specific interests either of investors or of occupiers. The IRE_BS International Real Estate Business School has been working in collaboration with Fraunhofer Institute for Industrial Engineering IAO and German Society for Real Estate Researchers on the development of OFFICE SCORE for two years. In October 2007 the first phase of the project could be finialized.