PURPOSE: To increase horizontal deformation capacity of a bearing wall by a method wherein vertical forms are extended upward of an upper lateral beam to form a plastic deformation part.

CONSTITUTION: Vertical forms 1 and 1 formed approximately square shape in cross section and lateral beams 2 and 2 are combined together to form a bearing wall of a frame approximately in a rectangular shape. The vertical forms 1 are extended upward of the lateral beams 2 located to the upper part and the extension part forms a plastic deformation part 4. In this case, the plastic deformation part 4 has length being approximately three times or more as long as the size of the vertical forms 1. Braces 3 are arranged in square shape in cross section in a similar manner described in the vertical forms 1 and the lateral beams 2 such that the central parts of the adjoining vertical forms 1 and lateral beams 2 are connected. By applying bending yielding on the plastic deformation part 4, the horizontal deformation capacity of a bearing wall is increased through plastic deformation.