Structural design is a highly specialized area of civil engineering. It can be described as a set of methods or tools that are used to determine safe and economical specifications for a structure, and to ensure that a planned structure will be sufficiently strong to carry its intended load. Structural engineers conduct a structural analysis to determine what internal and external forces could affect the structure, then design a structure with the appropriate materials and reinforcements to satisfy the requirements. There is a strong relationship between the professional disciplines of architecture and structural engineering. While architects are normally tasked with designing the visually appealing features of a project, structural engineers place their focus on strength, durability and safety when designing a building.Structural engineers combine the core principles of structural design with a sound background in physics and materials science to ensure that structures are built to withstand the loads and forces that they will encounter during their usage. Civil engineers that design structure for construction projects must be excellent problem solvers. The decisions that structural engineers make during the structural design phase of the project will affect everything from the project cost and duration to the ultimate safety and viability of the structure.