According to office building design in Korea, building exterior and office automatic systems through introducing IB system have been improved. However, the lower floors of a building are functionally easy to transfer but actually functions as an enterance. Although at takes a large investment by the owner or enterprise, mainly the tenants and neighbors are in a broad sense the actual users. In this point of view, the lobby of an office bulidling which is the connection between the exterior as a public space and the interior as a private area, does not only have the function of an enterance but also has to be an image of the enterprise or the building itself. Therefor the lobby must contain various functions of space.