This study presents combined system of rotational friction dampers connected to high strength tendons to enhance both seismic and progressive collapse resisting capacity of existing structures. Friction dampers were designed using the capacity spectrum method to satisfy given performance objectives against seismic load, and their seismic and progressive collapse resisting capacities were investigated. According to the nonlinear dynamic analysis results, the structures retrofitted with rotational friction dampers generally satisfied the given performance objectives against seismic load. Both the nonlinear static and dynamic analysis results showed that the progressive collapse potential of the model structures was significantly enhanced as a result of the seismic retrofit.