There is no doubt that there has been a significant promotion of energy efficiency in buildings in the European Union following the adoption of the Energy Performance of Buildings Directive buildings in 2002 (Jansen, 2005). This trend towards energy efficient buildings has recently started to manifest itself in Greece. However, scientific research related to the energy and environmental performance of buildings has evolved towards an orientation towards occupant comfort and the perception of a building's performance (Steemers and Manchanda, 2010). This study attempts to fill a knowledge gap regarding office building design in relation to user experience and building performance in Greece. The recognition of climate change by scientists, politicians and the general public as a great challenge has led to the adoption of conservation measures. measures all resources, energy, water and materials, and encouraged sustainable development and construction practices. In the definition of sustainable development, which requires that “development meets the needs of the present without compromising the needs of future generations” (WCED, 1987), buildings have an important potential role. As they are made from long-life, energy-intensive materials and are passed down to future generations, if they do not meet the needs of the future then they cannot be considered sustainable . Furthermore, they are responsible for a large part of the consumption of natural resources and, therefore, greenhouse gas emissions (Fisk, 2001). In the context of sustainable development, buildings have begun to be seen as positive and important capital assets for the achievement of organizational goals and corporate well-being. be. As a manager...... middle of paper ......y the efficiency of each building must be assessed and require landowners to present the energy rating certificate before selling or renting a building ( CRES, 2009). This certificate would simply indicate the annual energy consumption of a building and therefore the annual quantity of CO2 it produces. This regulation will replace the regulation on thermal requirements for buildings put in place in 1979, which indirectly refers to the energy performance of buildings by making it compulsory to apply thermal insulation in all new buildings but without taking into account solar gains. or any other source of thermal gains (Papadopoulou, 2009). This change is illustrated in Figure 1.3. The new regulations also cover existing buildings that will be renovated, which is very important since only a tiny percentage of new buildings replace the country's old building stock each year...