Current rents are determined by the market. They are the result of both supply and demand. In order to estimate if the own cost situation fits to the market rents and market sales quota, the real estate companies have to create a reverse rent calculation with their planned prospective cost situation. Calculations on a Cash Flow-base don't have the warranty of fitness for the special purpose of reverse rent calculation because of the volatile Cash Flow-trends and the inclusion of cash outflows with investment characteristics. Therefore the aim is to adapt the multi-stage contribution margin systems, which are state of the art in the industry, for the use in the residential real estate industry.

The contribution margin system has to be expanded to a statement of changes in contribution margins. There are variances in ascending powers, which have to be checked in a variance analysis. These variances are caused in different dimensions of the data models of the residential real estate companies. The use of an OLAP-System will be helpful for the classification and interpretation of the variances.