This paper aims to highlight a possible strategy to improve the dynamic behavior of an existing building, built between 1930–1940, with vulnerabilities in terms of current seismic demand, by equipping it with a dual-function external structure. In the first phase, the main function is to provide more evacuation paths in case of fire and secondly, the external frame attached to the basic building, equipped with fluid dampers, has the function of increasing the critical damping, and respectively to reduce the seismic requirement for the existing building. The strengthening strategy is in accordance with the local seismic requirements, and design code P100-1. This strengthening proposal is intended to demonstrate the dual approach for seismically vulnerable buildings built in the interwar period in Bucharest, in a dense urban context. Mainly, several options of incorporation of viscous liquid fluidic dampers, and the impact of the positioning geometry in the dynamic analysis are considered.