§ 146

If the landlord provides heating and hot water, and the expenses for this exceed half of the rent for the relevant period according to the most recently issued heating account for one year, the tenant representatives or a majority of the tenants may demand that all or some of the works related to heating and hot water specified in an energy plan, cf. the Act on the Promotion of Energy Savings in Buildings, be carried out. If there is no energy labeling with an accompanying energy plan, cf. the Act on the Promotion of Energy Savings in Buildings, the tenants may, if the situation falls under the first sentence, require the landlord to carry out such energy labeling. It is a condition that the tenant representatives or a majority of the tenants simultaneously agree to a rent increase to cover all expenses resulting from the execution of the works, cf. § 129.