Mathematically the distinction between land and improvements in the income approach will have no impact on the overall value when the remaining economic life is more than thirty years. For this reason, it has become quite common to use the Vereinfachtes Ertragswertverfahren (simplified income approach), omitting the land value and the Liegenschaftszins. However, the separate treatment of land and buildings leads to more precise results for older buildings, especially for commercial buildings, which typically have a shorter economic life than residential buildings.
Automated valuation models (AVMs) are growing in acceptance. These rely on statistical models such as multiple regression analysis, machine learning algorithms or geographic information systems (GIS). While AVMs can be quite accurate, particularly when used in a very homogeneous area, there is also evidence that AVMs are not accurate in other instances such as when they are used in rural areas, or when the appraised property does not conform well to the neighborhood.