Abstract: A building structure, especially an air raid shelter is formed from prefabricated tubular concrete elements (10) and end wall elements (11), the tubular concrete elements (10) being clamped between the end wall elements (11) with the aid of prestressed prestressing means or ties (12). The tubular concrete elements (10) have at least one stiffening beam (17, 18) extending all around them and at least the interstices between successive stiffening beams are filled with in situ cast concrete (13) reinforced by means of a crossbar (24), which in situ cast concrete encloses the prestressed prestressing means or ties (12). Two or more rows of tubular concrete elements (10) with end wall elements (11) can be placed beside each other to form a large building structure, especially an air raid shelter in which the stiffening beams (17) on the adjoining tubular concrete elements (10) engage each other in a comb-like manner and constitute columns.