Bai tap concrete wall and steel frame An overview of a number of issues related to design of hybrid structures with reinforced concrete central core walls and perimeter steel frames is presented. Various design options for steel or steel–concrete composite coupling beams and their connections to core walls, and connections between outrigger beams and core walls are discussed. Design guidelines are presented and are evaluated with reference to previous experimental data from tests conducted by the authors. By following the recommended design procedures, it is possible to ensure satisfactory cyclic behaviour in terms of strength and energy dissipation characteristics.