The invention relates to a method for manufacturing a blank structure of a rail vehicle, comprising the steps of: providing an underframe (60), producing an outer wall module (1) according to a tailor-made blank method in which the The cut metal plates ( 10 , 11 ) with different material properties are joined to each other by means of laser welding to form a side wall surface, so that the outer surface ( 18 ) of the side wall surface is produced at the butt joint without material change, and the outer wall module ( 1) the frame (4) formed by frame profiles (5, 5a, 5b) is joined to the inner side (17) of the side wall surface, and several outer wall modules (1) are joined to at least one central side wall section (81 ), wherein the outer wall modules ( 1 ) are bonded to each other to the ground by means of laser welding without offsets occurring at the joints in the outer surface ( 18 a ) of the side wall section ( 81 ), at least the middle side wall section ( 81) and optionally outer wall modules (1) configured as side wall end modules (94) and optionally end modules mounted on the chassis (60) and attached to the top elements (71, 72), wherein The step of producing the outer wall module (1) consists of joining a curved upper flange profile (2) to the side wall face, wherein the upper flange profile (2) closes the upper edge of the outer wall module and is butt-bonded to the material by means of laser welding Adjacent metal sheets (10, 11) of different properties without material abrupt changes on the outer surface (18) of the side wall, wherein the upper flange profile (2) comprises a The profile section (42) with the outer surface (18) curved towards the inner side (17) of the outer wall module (1); and in the step of joining the skeleton (4) on the inner side (17) of the side wall , 5a, 5b) with end-side abutment edges (19, 20, 21) mounted via a T-shaped abutment interface and fixed to the side wall surface including the upper flange profile via a laser weld (13) in a material-fit manner on the inside (17). Furthermore, the invention relates to the blank structure of the vehicle body and the outer wall module.