This lecture covers the fundamental aspects of structural design, focusing on ensuring safety and comfort in buildings. It discusses the influence of various factors such as loads, supports, topology, materials, geometry, proportions, and construction methods. Examples like the Versailles Wedding hall collapse and the Cathedral d'Amiens are used to illustrate key concepts. The lecture also explores the importance of material selection, proportions, and innovative structural designs through case studies like the Temple d'Apollon and the works of Baker et al., Muttoni, and Samyn & Latteur.