In this paper the results of a study conducted in cooperation with SEB Asset Management, EuPD Research Bonn Germany and carried out in Spring 2008 will be presented: The Office Tenantís Almanac 2008 ñ Factors at Work in Rental Decisions and Tenant Satisfaction. The study focuses on office tenants in Germanyís 20 largest cities based on population figures. This means that all cities with populations in excess of 300,000 are covered by the survey. In order to guarantee a sufficiently low confidence interval, which enables the extrapolation of observations about the individual locations, 150 interviews per city were incorporated into the analysis. The decision factors of the potential tenant as a customer for renting office space were analysed. The Office Tenantís Almanach 2008 quantifies the factors that influence rental decisions and tenant satisfaction and identifies specific potential for improvement. The outcome was rather astonishing. It delivers valuable indications and recommendations for developers, architects and landlords in order to develop, design or let office buildings successfully.