The study proposes a semiactive approach to control the dynamic response of a one-way plan-wise asymmetrical structural system by defining a set of closed-form analytical control algorithm to drive semi-active viscous devices in order to optimize different energy rates of the system to be protected, namely damping energy, elastic energy, kinetic energy and input energy. These algorithms are tested by means of a large numerical experimentation by modifying the main structural parameters of asymmetrical system and considering different accelerometric input signals. Finally, the seismic response both in terms of relative displacement and energy rates, has been comparatively evaluated in the case of uncontrolled and semiactivelly controlled systems, by using the proposed algorithms. Results showed the efficiency of the strategy, especially when flexible systems and high spread device configurations are taken into account.