This lecture continues the study of Frank Lloyd Wright’s architecture, focusing on his non-residential buildings, structural innovations, and mature design ideas. It examines the Larkin Building in New York as a revolutionary office building that redefined workplace design through the use of a central atrium, natural light from skylights, ventilation shafts, perimeter services, and integrated furniture. The lecture then discusses Unity Temple in Oak Park as a major milestone in modern architecture, highlighting Wright’s early use of reinforced concrete, binuclear (H-shaped) planning, spatial continuity, and the idea that interior space is the true essence of architecture. It explains concepts such as plasticity, continuity, destruction of the box, horizontal emphasis, and organic architecture. Further examples like the Imperial Hotel, Tokyo, Taliesin East and West, and textile block houses illustrate Wright’s use of local materials, seismic innovation, flowing spaces, natural light, and cultural influences (Japanese and Mayan). The lecture also introduces the Wasmuth Portfolio and its strong influence on European modern architects, showing how Wright’s ideas shaped the foundations of modern architecture worldwide.