When the SC structure is partially applied to a nuclear power plant building, an RC-SC connection part is generated between the SC wall and the RC slabs or RC walls. When the RC-SC connection part is generated, the compressive failure of the concrete near RC-SC connection part may occur if the difference in flexural stiffness between the RC part and the RC-SC connection part is large. Also, from the viewpoint of constructability, it is expected that a anchoring system which fixes the SC wall is required if the SC wall is raised above the RC wall. In this study, construction method with connection improvement is proposed to solve the problems expected from the structural and construction aspects.