Contrary to the previous legal practice, the supreme court (OGH) has fundamentally changed the case-law on the above-average location, which is the condition for the location surcharge to reference value rent, in a decision at the end of 2017. Thus, the above-average location can no longer be deduced from the higher proportion of basic costs than the standard dwelling, but it is necessary to examine whether, in individual cases, the location is better than the average according to the concept of traffic and the experience of daily life. As a benchmark, it is not the entire federal state that should be used, but only the area that would be considered as a fairly uniform residential area on the housing market.

This controversial decision has led to the fact that it is still unclear which premises of the above-average qualification should be assessed. This problem is also reflected in the location surcharge map, revised by the MA 25 (Municipal Department), by which it was attempted to consider the instructions from OGH in the calculation. The used methodology leads to massive market distortions. The challenge is to bring the relevant factors for the respective location into an approximately objectifiable overall system.