Book excerpt: Structural control offers opportunities to design new structures and to retrofit existing structures by the application of counter-forces, smart materials, frictional devices, etc., instead of just increasing the strength of the structure at greater cost.The Association for the Control of Structures (ACS) is promoting in Europe the development of this new technology in architectural design and infrastructure renewal and rehabilitation. The First European Conference on Structural Control was organized as one of the major initiatives toward this objective.