(1) An agreement deviating to the disadvantage of the lessee from the provisions of the present Subchapter is ineffective. This applies to agreements on the rent amount at commencement of the lease only insofar as the permissible rent is exceeded. The lessor is to surrender to the lessee the rent that has been paid in excess in accordance with the provisions on the surrender of unjust enrichment. Section 814 and section 817 sentence 2 are not to be applied.
(1a) To the extent the permissibility of the rent is based on section 556e or section 556f, the lessor is under obligation to inform the lessee, without this needing to be requested, of the following prior to the lessee making their declaration as to the conclusion of a contract:
1. in the case governed by section 556e (1), the amount of the rent paid previously,
2. in the case governed by section 556e (2), that modernisation measures were performed in the last three years prior to commencement of the lease,
3. in the case governed by section 556f sentence 1, that the dwelling was used and let on a lease for the first time after 1 October 2014,
4. in the case governed by section 556f sentence 2, that the lease is the first-time lease following comprehensive modernisation.
Insofar as the lessor has not provided the information, they may not rely on a rent that is permissible under the terms of section 556e or section 556f. Where the lessor has not provided the information and has done so subsequently in the form required, they may rely on a rent that is permissible under the terms of section 556e or section 556f only two years after having provided the information subsequently. Where the lessor has not provided the information in the form required, they may rely on a rent that is permissible under the terms of section 556e or section 556f only once they have subsequently provided the information in the form required.
(2) The lessee may demand that the lessor repay rent that is not owed pursuant to sections 556d and 556e only if the lessor has objected to a breach of the provisions of this Subchapter. Where the lessor has provided information in accordance with subsection (1a) sentence 1, the objection must refer to the information so provided. Where the lessee objects to the violation more than 30 months after commencement of the lease or where the lease already had come to an end at the time the objection is received, the lessee may demand repayment only of the rent that fell due after receipt of the objection.
(3) Upon the lessee’s demand, the lessor is obliged to provide information regarding those facts that are relevant to the permissibility of the agreed rent under the provisions of this Subchapter, inasmuch as these facts are not generally accessible and it is easily possible for the lessor to provide information in this regard. Section 559b (1) sentences 2 and 3 applies accordingly to information regarding modernisation measures (section 556e (2)).
(4) All declarations pursuant to subsections (1a) to (3) require text form.