The Issue of daylight inclusion in the office buildings has got the significant importance in the recent years. Using this light, dependence on artificial lighting sources can be reduced which results in the energy efficiency. This study aims to determine the optimal Window Wall Ratios in the office buildings of Tehran to take the advantage of daylight abundance regarding the climatic features without making the designers involved with the complicated calculations. All the research analyses have been done based on the window models comparison through the computational simulations. After the primary analyses, the models were developed and put to the test again. The study shows that among from all the tested models, an optimal WWR range for the office buildings of Tehran can be proposed.