This paper presents the overview and problem definition for a benchmark structural control problem. The structure considered—chosen because of the widespread interest in this class of systems—is a scale model of a three‐storey building employing an active mass driver. A model for this structural system, including the actuator and sensors, has been developed directly from experimentally obtained data and will form the basis for the benchmark study. Control constraints and evaluation criteria are presented for the design problem. A simulation program has been developed and made available to facilitate comparison of the efficiency and merit of various control strategies. A sample control design is given to illustrate some of the design challenges. © 1998 John Wiley & Sons, Ltd.