Reverberation time is often used as a design parameter in connection with the acoustic design of rooms. Reverberation time denotes how quickly sound energy disappears in a room. In order to obtain good speech acoustics in classrooms, school premises, a sufficiently muted environment in day care centres and after school centres, a calm and relaxing environment on hospital wards, appropriate acoustics in offices, etc., there are guidelines with respect to suitable reverberation times. In most cases, acoustics measures involve the addition of some form of sound absorbing suspended ceiling to the rooms. In order to be able to predict the reverberation times with reasonable degree of precision in such cases, it is necessary to take into consideration the effects of sound-reflecting furniture such as chairs, tables, bookshelves, etc. In this project, we intend to evaluate a model for the quantification of the effect of furniture on the reverberation time. The model is based on a concept that makes it well suited to existing models for calculating reverberation time in rooms with suspended ceilings such as the model on which the European Standard prEN 12354-6 is based.