A 20-year rent index can not be used as a justification for a rent increase. The tenant could not read whether the increase is justified or not, decided the Federal Court (BGH). The increase in rent is therefore ineffective for formal reasons.
A tenant in Magdeburg had received mail from the property management at the beginning of 2017. It stated that the rent for their 79-square-meter apartment should rise by 60 euros to 360 euros. This was justified by the city rent index from the year 1998. The woman did not agree. The dispute went through the instances.
In principle, landlords can raise the rent to the local comparative rent, as long as there has been no increase in the last 15 months. But this must be justified to the tenant comprehensible. The Mietspiegel is an option. By law, it should be updated every two years.
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If there is no current rent index, the landlord may in principle also use an outdated. According to BGH, however, 20-year-old data are no longer suitable. The housing value of a property is "typically changing as time progresses," the judges explained in the verdict. Thus, a device that was once special, over the years become the standard equipment.
The landlord must justify the rent increase differently. He can, for example, refer to three comparable apartments.
Rent levels are collected in most major and many smaller cities. They depict both new lease rents and changes in existing rents and are intended to give an impression of how many tenants really pay in the respective cities. The so-called "local comparative rent" is not only used by landlords and investors, but also by the legislator as an indication, for example in the rental price brake.
File number: VIII ZR 340/18