ABSTRACT The conventional structural design of buildings often neglects the significant contributions of the coupling action of the floor slabs, potentially leading to unsafe designs against seismic actions. The interaction between reinforced concrete (RC) frames and shear walls, especially through slabs, plays a crucial role in the structure’s behaviour under seismic loading. In Australian construction, where wall-type systems are prevalent, it is essential to understand the complex interactions between coupled walls and columns facilitated by slabs. This study addresses this issue by proposing an innovative strain-based model, validated through finite element analysis. The proposed model, when compared with existing simplified models, demonstrates superior accuracy and effectiveness. This innovative approach not only enhances our understanding of seismic behaviour but also offers a straightforward solution that can be easily implemented in practice. Key findings reveal that slab interaction increases material strain and inelastic force capacity while reducing displacement capacity, particularly affecting smaller elements like gravity load-carrying columns. This improved understanding can lead to more effective strategies for enhancing the seismic resilience of RC buildings.