This paper will give the experiences of the major housing federations in Germany (GdW Bundesverband deutscher Wohnungs- und Immobilienunternehmen e.V. and Verband Berlin-Brandenburgischer Wohnungsunternehmen e.V.(BBU). The members in Germany ñ housing companies and cooperatives host more than 7.000.000 housing units. The paper is a follow up paper to Prof. Dr. Bach and demonstrates the results of Facility Management in the housing sector in Germany. It will also give a report of the success of working groups of specialists in education and research, experts in Facility Management and advisors in the major housing federations. In the housing stock in Berlin and Brandenburg (1,2 Million housing units; thatís 40% of all the housing stock in these states), which is hosted by the members of BBU, in the last 10 years Facility Management was very successful in lowering the operating costs. In the year 2004 tenants in Berlin in Brandenburg had to pay less operating costs than in the middle of the 90th; without changing the high standard in services. Benchmarking with the ìGeislinger Konventionî demonstrates, that in 2004/2005 the operating costs could be lowered, though the prices for energy and housing services increased in the same time. Such experiences exist also in some other regions of Germany and will be explained. The paper will show that the new tool of benchmarking systems is not only successful for describing the operating costs, their influences and measures of facility management because it can also be used for identification of energy efficiency and CO2-emissions of buildings. So it will be demonstrated how to use an electronic tool for facility management in the housing sector for new management challenges in climate protection and improving the energy efficiency in housing.