Do all structures have to withstand external forces?

All structures must be designed to withstand external forces to ensure their stability and safety. External forces can include gravity, wind, snow, earthquake forces, and more. The fundamental principle of structural engineering is that a building or structure needs to support its own weight while also managing additional loads that can act upon it during its lifetime.

For example, a building will have to deal with gravitational forces resulting from the weight of its materials, occupants, and furnishings. Additionally, environmental factors such as wind can create lateral loads, while seismic activity can impose dynamic forces that structures must absorb or resist.

Therefore, the assertion that all structures need to withstand external forces is correct, as this requirement is a universal aspect of safe architectural design. Each design will depend on specific conditions and codes relevant to its location but ignoring the need to account for these forces would lead to inadequate safety measures and potential structural failures.