(1) Where the rent last owed by the previous lessee (rent paid previously) is higher than the rent permissible pursuant to section 556d (1), a rent may be agreed in an amount up to the amount of the rent paid previously. Abatements of the rent as well as those rent increases that were agreed upon with the previous lessee in the course of the last year prior to termination of the lease are not taken into account in determining the rent paid previously.
(2) Where the lessor has taken modernisation measures in the sense of section 555b in the course of the last three years prior to commencement of the lease, the rent permissible under section 556d (1) may be exceeded by that amount that would result in the event of a rent increase pursuant to section 559 subsections (1) to (3a) and section 559a subsections (1) to (4). In performing the calculation pursuant to sentence 1, the reference rent customary in the locality (section 558 (2)) is to be used as a basis that would be charged at the commencement of the lease without taking account of the modernisation.