A study on the seismic retrofit of RC buildings using hysteretic dissipative braces is presented in the paper. By following a displacement-based design procedure, a fully multimodal approach based on an adaptive version of the capacity spectrum method is followed. Then, a dual RC-damped brace system idealized as bilinear is considered thus accounting for the effects of frame-damped braces interaction. Finally, the optimal distribution of dampers is determined using an iterative procedure. The proposed method is validated using nonlinear static and dynamic analyses. The results have shown the effectiveness of the proposed procedure to address the main issues of seismic design of damped braces: effect of force demands to the frame due to the dampers, higher modes contribution and effect of soft story irregularities.