European building regulations currently focus on the reduction of carbon emissions by reducing the primary energy demand for building operation. The embodied energy in construction materials is not limited by building regulations. In this study the potential for carbon savings by optimizing the grey energy, embodied in residential buildings in Germany, was analyzed. Therefore, representative sample buildings for the German building market were analyzed. Based on detailed statistical data about the German construction industry, results were transferred to the current building activity. An enormous saving potential was determined. The global warming potential (GWP) of shell constructions could be reduced by up to 77% with existing technologies and without additional investment costs. Environmental cost savings of more than 1 billion sic/yr could be realized for the German economy. With additional investments the saving potential could be increased to 95%. Though, such cost-intensive improvements would not be cost-efficient. Compared to further tightening of requirements on the energy efficiency the potential of reducing grey energy is much easier to tap. Thus, it is a reasonable next step to introduce requirements on the maximum GWP by grey energy in building regulations. Suggestions for such policy implementations were made. (C) 2016 Elsevier B.V. All rights reserved.