The construction industry has a major influence on man-made carbon dioxide emissions. Being sustainable also means reducing or neutralizing our carbon dioxide pollution in the future. This research and the corresponding work are therefore guided by the following question: Is it possible and useful to conduct life cycle assessments and at the same time analyze the environmental impact of the construction sector? In the context of this work, a life cycle assessment of a building is performed using the example of a hotel building. All construction elements of the thermal envelope are examined from an environmental point of view by considering the global warming potential of each part of the construction. The aim of the study is to draw conclusions about the parameters that are decisive for the construction of a hotel building from an ecological standpoint in the production phase. Based on the results of the study, we want to drive the development of a “future” energy performance certificate forward that graphically illustrates the evaluation of buildings under both aspects - energy efficiency (final energy) and sustainability (GWP - global warming potential).