The German government has set ambitious climate protection targets to limit global warming. The goal is to achieve an energy efficient and almost climate-neutral building stock by 2050. This will require, among other actions, a reduction of the primary energy demand of buildings by up to 95% by the end of 2050. In order to achieve an almost climate-neutral building stock, measures for deep energy retrofit are required. In addition to an existing financial demand, there are additional barriers to the expansion of activities to improve the energy performance and to reduce greenhouse gas (GHG) emissions of the existing building stock. One way to overcome these barriers are novel business models such as Energy Performance Contracting (EPC). The question arises as to whether and how the reduction of GHG emissions can be taken into account in the savings guarantees as they are typical for EPCs. This and other questions are addressed in the paper using conjoint analysis. Among other results, it is pointed out that specific approaches are required for different target groups such as the public sector and private homeowners. Finally, recommendations for further action are given. ... mehrThe presented partial results are drawn from the research work "Analysis of business models with regard to their potential for GHG reduction and energy efficiency of buildings".