(1) The lessor is to announce a modernisation measure to the lessee at the latest three months prior to its commencement in text form (modernisation notice). The modernisation notice must include information on:
1. the nature and the likely extent of the modernisation measure in its essentials,
2. the likely commencement and the likely duration of the modernisation measure,
3. the amount of the anticipated rent increase where it is intended to demand an increase in accordance with section 559 or section 559c, as well as the anticipated future operating costs.
(2) As a rule, the lessor is to notify the lessee in the modernisation notice of the form and the time limit of the hardship objection defined in section 555d (3) sentence 1.
(3) The lessor may refer, in the modernisation notice concerning a modernisation measure under section 555b nos. 1 and 2, to generally-recognised standard values, in particular with regard to the quality of construction components in terms of energy efficiency.
(4) Subsections (1) to (3) do not apply to modernisation measures that only entail an insignificant impact on the leased property and merely will lead to an insignificant rent increase.
(5) A deviating agreement to the disadvantage of the lessee is ineffective.