shape as shown in fig1 to 3 and structured to be preset to a diameter affording fitting the inner surface of the second fitted annular body 7 onto the outer peripheral surface of the first fitted annular body 6 by taper press fitting a wedging action is generated also in the embodiment the building members such as the columns 1 beams 2 or the like are hollow bodies formed from concrete concretely molding of the columns 1 and the beams 2 is carried out by means of a so called hollow centrifugal molding technique the so called hollow centrifugal molding technique is one in which a square shaped form is rotated while concrete placing is performed and when rotation of the form is stopped and the form is removed inner circular holes 1 a 2 a are formed centrally in the longitudinal direction of the form a hollow body obtained by the hollow centrifugal molding technique is very rigid since centrifugal forces press the concrete in the embodiment the square cylinder form is used to make the columns 1 and the beams 2 square in cross section in a direction perpendicular to the longitudinal direction and the inner holes 1 a 2 a are circular also in the embodiment the columns 1 and he beams 2 are formed to be of a pc concrete structure prestressed concrete structure in which steel wires 11 piano wire reinforcement or the like as tension members are introduced.