Abstract: The prefabricated building frame structure or gazebo is of octagonal configuration and has a centrally located vertical axis. It includes a structural support system, a floor system carried by the support system above ground level, and a roof system carried solely by the support system. The floor and roof systems are provided with collars, each with at least three sides, which are spaced apart and are located on the vertical axis. The structural support system includes at least three vertical support columns with each column being spaced an equal distance from the axis and being spaced equal distances from adjacent columns to form the octagonal configuration. The floor system includes joists of equal length, one for each collar side and corresponding column. The joists extend from the floor collar to the support columns. The sides of the roof collar and the upper end portions of the support columns are provided with fastening brackets.