This lecture covers the conceptual seismic design of buildings, focusing on the choice of structural systems, construction materials, and guidelines for seismic behavior. It emphasizes the importance of simple and robust structures, the need for joints to prevent pounding, and the selection of stiff floor systems. The instructor discusses the significance of slender walls, adequate foundations, and the interaction of masonry infills with reinforced concrete frames. The lecture also addresses the impact of seismic events on non-structural elements, highlighting potential consequences and the importance of cooperation between architects and engineers in seismic design.