For your housing based on a hereditary building right (Erbbaurecht) a higher ongoing payment is being demanded. Alongside the existing loan this could reduce your monthly leeway. Before you finally accept the new amount, two checks are necessary: the legal or contractual basis and the personal financial consequence. Neither replaces the other.
Connect the letter to the correct contractual status
Secure the contract, addenda, previous increases and the current letter. Note the demanded amount, the intended start and the calculation given. First check whether the annual and monthly figures use the same basis. A misunderstood period can already skew your own budget calculation.
An unclear claim is not thereby confirmed as effective merely because you can calculate it as a precaution. Conversely, a tight personal household budget does not alone decide its legal legitimacy. Obtain appropriate advice for open questions.
Read the legal limit only in the appropriate context
§ 9a ErbbauRG contains limits for residential purposes where a change in the agreed hereditary building ground rent (Erbbauzins) is provided for. The provision refers, among other things, to equity (Billigkeit) and general economic conditions and describes exceptions. A claim for an increase can be asserted at the earliest after the three‑year intervals mentioned there. In the case of partial residential use an appropriate portion is dealt with separately. [ERBBAU9A]
This does not yet calculate which increase your contract allows. In particular a general increase in land prices is not applied as an appropriate basis without examination. The actual clause and the temporal development must be professionally assigned.
Calculate the payment difference alongside it
In the fictitious example an assumed annual amount rises from 2.400 to 3.000 euros. The difference is 600 euros per year or, calculated evenly, 50 euros per month. That says nothing about the legal admissibility of this example increase.
If the actual payment method differs, the cash requirement must fit the actual due date. The monthly reserve for the annual amount is an organisational decision of its own, not a change of the agreed due date. Place the additional burden beside the loan instalment and other housing payments.
Work on with two separate results
Record which basis is still being examined and which provisional financial effect you have calculated. Clarify the appropriate reaction to the specific letter in good time. The article does not recommend unilaterally stopping payments and does not state any general deadline for objection.
If the legally appropriate amount is confirmed, the ongoing planning is updated accordingly. If a dispute remains, it remains visible as such. In this way an increase is neither acknowledged by a purely personal budget line nor dismissed by an inappropriate general percentage rule. Contract and affordability each receive the examination they need.