The comparative rent as a local comparative rent is formed from the usual fees (regulated in (2 ) BGB ) that have been paid in the municipality or a comparable municipality in the past six years for living space of a comparable type, size, equipment, quality and location including the energetic quality and equipment have been agreed or changed. When determining living space, where the rent has been determined by law ( cost rent ) or in connection with a funding commitment ( approved rent ) ( social housing , rent control ), is not taken into account .
In the municipalities in Germany in which there is a rent index (approx. 450 out of 20,000), the comparative rent is shown in the rent index. If there is no rent index, the comparative rent can be verified by the landlord to the tenant via an independent rental database (only in Hanover), at least three comparable properties and / or an expert ( (2) BGB).
Landlords experience disadvantages in terms of income tax if they rent an apartment for less than 66% of the local market rent for residential purposes. In this case, the transfer of use is to be divided into a paid and a free part ( (2 ) EStG ) so that income-related expenses cannot be fully deducted from the tax.
In the case of commercial premises, the comparative rent can be calculated from statistics free of statutory regulations. The local chambers of industry and commerce sometimes provide information on this area.