The exterior envelope of buildings play a significant role on the amount of energy consumption in office buildings that are located in warm climates. The present study focuses on the reduction of energy consumption by integrating daylight and artificial lights, and by changing the characteristics of exterior envelope of buildings including window coverage and dimension of buildings. Moreover, the study focuses on the impact of mentioned parameters on the cooling load and lighting in office buildings. For this study, a typical office building located in warm climate is simulated, using the software eQUEST. It is found that by changing the window type (glazing and coverage) and integration of daylight with artificial lights, a significant reduction occurs in the amount of energy consumption. In this article, an office building is simulated with insulated double window transparent that has fins and overhangs with ratio of northern-southern to eastern-western side equal to four.  By using daylight to provide some parts of lightings, a reduction of 45%, 16% and 20% is found on lighting, cooling and total energy consumption, respectively. This energy reduction is compared with a building that uses clear windows with no daylight being used to provide lighting in the office building.