KfW Darlehen
KfW Loan
These are subsidized loans from a bank affiliated to the German State, KfW. This bank also provides loans to first-time buyers of owner-occupied real estate and for certain construction projects that reduce CO2 emissions. In order to be able to receive such a loan you need to apply for it at the bank which is handling the main part of your mortgage. Often it is understood as a measure minimizing the risk of the main bank and the interest rate of the main loan can be reduced.