Most designers and energy resources managers today are concerned about the multiplicity of buildings in which energy considerations have not been taken into account. The result is the bioenvironmental and energy crises. Also, the uncontrolled consumption of energy in buildings is associated with both the risk of putting an end to non-renewable energy resources and an increase in the maintenance costs. Previous research suggests that turning courtyard into atrium can be an appropriate solution by lowering the wastage of thermal energy. In educational settings such as universities, the greenhouse effect of an atrium in cold seasons can be an appropriate alternative for keeping the adjacent spaces warm and lowering the use of thermal systems. The present study was conducted to determine the rate of decrease in thermal energy consumption by covering the courtyard using an energy simulator on the building of the faculty of engineering at Hakim Sabzevari University, Iran. In order to prevent the greenhouse effect of the atrium in warm seasons, skylights are installed for letting the air out. Based on the simulation of atrium and courtyard models, the results showed that the heating load of the courtyard model is much higher than the atrium model in winter. Consequently, the heating function of the Faculty building improved by 27% when converted to atrium model.Keyword-Atrium, Courtyard, Energy use, Hakim University, Sabzevar I. INTRODUCTION The energy efficiency of built environment in urban areas plays an important part in lowering the problems of climate change, resource diminution, and environmental challenges at large [1]. Building energy consumption level will be on the rise in near future [2]. According to [3], due to higher contemporary living standards and rapid urbanization, the energy-consuming appliances such as air conditioners and urban building areas will lead to an increase in energy consumption by human beings [3]. In order to reduce the wastage of energy, transitional spaces are generally considered for receiving natural light and air [4][5][6][7][8][9][10]. Throughout the history, human beings have used such spaces for over 5000 years [11,12], and different types of these have been introduced for various purposes. These spaces may include a multiplicity of spaces from a balcony and a corridor to a courtyard or an atrium.Transition zones may be assumed as architectural spaces where the indoor and outside climate is moderated without applying HVAC systems. Consequently, those living in such buildings may experience the dynamic effects of changes in the outdoor climate. In addition, transitional spaces variously interact with the outdoor environment depending on the climate.In a relative study, Aldawoud and Clark [13] searched the thermal performance of the same geometric proportions of atrium and courtyard for four diverse climate types; they concluded that courtyard displayed better for low rise buildings, but noticed the closed atrium much better for longer buildings. According to Aldawoud and Clark [...