The present invention provides construction configurations and a construction method for steel houses that eliminate the shortcoming of the conventional platform construction method for steel houses that complicates the structure because of the need to use metal reinforcements without losing the advantage of the conventional method that facilitates the construction work by using wall panels. After constructing the ground story wall (lower story wall) 22 by attaching wall panels 21 for the ground story to through vertical frame studs 20 extending to upper floors, the second story wall (upper story wall) 23 is constructed by attaching wall panels 21 for the upper Story to the through vertical frame studs 20. Of the wall panels 21 disposed along the four sides of the lower story, the top ends 29 of the two opposite wall panels 21b are positioned lower than the top ends 29a of the lower story wall panels 21a on the other two opposite sides. Both ends of the floor panel 24 are mounted on the lower top ends 29 of the wall panels 21b.