The benefits obtained through the application of exergy concept in buildings are currently known, since they contribute to the proper use of energy as well as to a better adequacy of the different energy qualities taking part in a facility. Besides, an exergy analysis supports the identification of both the economic and environmental cost formation in every phase of the energy transformation chain. Those type of studies are known as exergoeconomic and exergoenvironmental analyses. In this work, a nearly zero energy buildings (nZEB) single-family dwelling is analyzed, where heating and DHW exergy demands are hourly calculated. A full exergetic analysis of its building envelope and thermal facility is carried out and exergoeconomic and exergoenvironmental analyses are applied. The aim of this study is to show the enormous possibilities for the energy efficiency improvement that still exist, which cannot be appreciated through a common energetic analysis (being the facility's energetic efficiency of 81% and exergetic one of 13%). In addition, the results of this study indicate the location and the correct assessment of the real inefficiencies.