In addition to 2D drawings, we also perform 3D BIM work; BIM is well suited for studying spaces. As shown in the following case, a BIM study is useful on a rooftop where equipment is concentrated. In an office where the same layout floors are stacked on top of each other, it is possible to save labor by studying only one representative floor. It is also used for lighting simulation. We mainly use Rebro and Revit as BIM software for equipment however we also hold training and study sessions.