(1) If the lessee is to bear the operating costs for heating or hot water, and if the lessor converts the supply from internal supply to an independent commercial supply from a heat supplier (heat supply), then the lessee is to bear the costs of heat supply as operational costs if
1. the heat is supplied more efficiently, either from a new system constructed by the heat supplier or from a heat network, and
2. the costs of heat supply do not exceed the operating costs for the previous internal supply of heat or hot water.
Where the annual utilisation rate of the existing system prior to conversion is at least 80 per cent, the heat supplier may restrict itself to improving the operation of the system instead of the measures in accordance with no. 1.
(2) The lessor is to announce the conversion at the latest three months in advance and in text form (conversion notice).
(3) The Federal Government is authorised to enact provisions, by statutory instrument without the approval of the Bundesrat, for heat supply contracts that are concluded in the case of conversion under subsection (1), as well as for the requirements in accordance with subsections (1) and (2). In this context, the concerns of lessors, lessees and heat suppliers are to be adequately taken into account.
(4) A deviating agreement to the disadvantage of the lessee is ineffective.