Point: 4.3 Is it also possible to meet the required minimum proportion of energy from renewable sources through “increased efficiency” alone (cf. lit. b, fourth indent)?

Yes, the required minimum proportion of energy from renewable sources can also be demonstrated by “increasing efficiency” alone (e.g. by exceeding the requirements for the building envelope or by a corresponding improvement in the heating technology energy requirement). The phrase “any combination” therefore also includes the application of only one of the measures listed.