A desire rent a landlord is only effective if it is significant to the formal rules of the legislature holds. Remember these are not the landlord, the rent demanded to be void. In certain cases, however, is also a multiple rent is not excluded.
A year blocking an increase in rent
In principle applies: the landlord wants the rent to the local rental comparison (Section 558 BGB) raise, he must a vesting period of one year between the last rent and the new rent to comply with the request.
The exception:
The embargo is not, however, in the event of a voluntary rent. The tenant has, for example, a higher rent at a modernization already agreed, the landlord the rent shortly thereafter still on the corresponding Ortsniveau raise.
The concrete case
A tenant had referred to a rent demanded by the landlord pursuant to Section 558 para 1 BGB rely on that in the previous year to increase the rent due to upgrading work pursuant to Section 559 BGB between the tenants had been agreed. Subsequently, the Federal Court (BGH), but in a ruling that an increase of the rent will still be called by the landlord if the tenant because of a recent modernization voluntarily with a higher rent was agreed (BGH, ruling of 18.07.2007 , Az VIII ZR 285/06).