Energy conservation is a popular topic in scientific research today, despite the specific effects of energy conservation awareness still being investigated. Significant research about this topic has been performed in different countries. However, the research conducted so far concerns methods of energy saving, a building’s energy efficiency and new technologies; however, a significant part of society will live in technologically old buildings for a long time, which requires the involvement of consumers to save energy. To explain how energy-saving awareness plays a role in energy-saving behavior, this study will take city dwellers as a research facility and integrate relevant literature and disciplines, such as information and knowledge management, with the mechanistic study of how energy-saving awareness influences behavior that conserves energy and establishes a sensible behavior model. The survey was conducted in Poland, Portugal and Italy with over 18,000 people who declared that they are responsible for managing the household. In addition to the quantitative and qualitative research defining the percentage of behavior, the research group gave answers to the assessment of energy management, both assessing itself and the activities carried out in its own households on the Likert scale. The SERVPERF method was used for this. The results of the study clearly show that not only do economic factors affect energy saving, but also an informed society that cares about resource management. The research carried out presents the measures undertaken to save energy, and also identifies the level of knowledge and behavior that reflect pro-ecological trends and care for the sustainable development of the city, country and one’s own household.