Mehregan office Building, has nine floors, three of which are underground and are used as parking. Considering the company’s activities in the field of industrial equipment and client’s wishes, creating a geometric form and building with transparency, became the main design idea. To achieve this, considering the direction of the building, facing the south, controlling light and shadows and also exposing the buildings official activity, were crucial in the design. Then according to the location of column in the façade and vertical circulation box, central part of façade was designed transparent in order to direct light inside. Two solid boxes were then put on each side to control the light. Connection to the ground was defined by breaking the pattern and exposing the columns, extending them to the first floor to emphasis on the entrance. Thus, a rational attitude posing in the interior of the body associated with aesthetic and functional space that could be associated with generous space.