The brief analysis of the key points of the Gebäudemodernisierungsgesetz examines the potential consequences of the planned legislative changes for the German residential building sector up to 2044. The analysis compares the current “Gebäudeenergiegesetz” (GEG 2023) with the new key points of the “Gebäudemodernisierungsgesetz” (GMG 2026). The comparison is placed in the context of the European Energy Performance of Buildings Directive (EPBD), which stipulates stricter zero-emission standards for new buildings from 2030 onwards. In addition, the effects of a possible change in the law are examined using the EWI building model. The results of the modeling show that the potential increase in the installation of oil and gas heating systems could raise the demand for fossil and climate-friendly fuels to a total of 216 TWh in 2044—compared to 158 TWh under the stricter GEG requirements.