This study develops an active control methodology for the AMD benchmark problem of Spencer, et al. (1997) based on dynamic output feedback controllers designed using an H1 based approach. Kalman lter estimators of the states of a reduced order model of the benchmark structure are coupled to static state feedback controller gains to develop the dynamic feedback controllers. A method is outlined for designing H1 feedback controller gains, and a comparison is made between the e ectiveness of H1 static output feedback and the dynamic acceleration feedback controllers. The results quantify the performance increase obtained with the additional complexity of the dynamic output feedback controllers compared to the static acceleration feedback controllers. Introduction For the AMD benchmark problem of Spencer, et al. (1997), controllers are designed using two H1 based approaches: one approach uses direct static output feedback of sensor measurements, and the second approach uses a dynamic output feedback controller that consists of static state feedback controller gains with a Kalman lter state estimator. The controllers considered in this study are designed by a continuous-time H1 controller approach, then discretized for simulation with the benchmark model. The controllers are developed from a state space design model of the form: _ x(t) = Ax(t) +Buu(t) +Bww(t) (1) z(t) = Czx(t) +Dzuu(t) +Dzww(t) (2) y(t) = Cyx(t) +Dyuu(t) +Dyww(t) (3) where x(t) is the state vector, u(t) is the vector of control inputs, w(t) is the vector of disturbance inputs, y(t) is the vector of sensor measurements, z(t) is the vector of regulated outputs, and A, Bu, Bw, Cz, Dzu, Dzw, Cy, Dyu, and Dyw are matrices of Assistant Professor, Stanford University, Dept. of Civil Engineering, Stanford, CA 94305. Research Assistant, Stanford University, Dept. of Civil Engineering, Stanford, CA 94305.