This knowledge area focuses on the primary materials used in structural engineering and how their mechanical properties, behavior under loads, and construction characteristics influence design decisions. Each structural material—such as concrete, steel, timber, masonry, and composite systems—offers unique advantages, limitations, and application scenarios based on load-bearing capacity, durability, fire performance, constructability, and cost.

Structural engineers must understand the properties of these materials, including strength, stiffness, ductility, and resistance to environmental exposure, as well as their compatibility with design codes and construction methods. This understanding is crucial for selecting the right material for each project, detailing connections appropriately, and ensuring long-term performance. The choice of material directly impacts the structural system, construction sequence, sustainability strategy, and overall lifecycle of the structure.

This section covers the five main material categories: concrete and reinforcement, structural steel and connections, timber and engineered wood, masonry and load-bearing units, and composite and emerging materials—providing a comprehensive foundation for material-specific design practices.