Foundation (engineering)
Foundations are designed to have an adequate load capacity depending on the type of subsoil/rock supporting the foundation by a geotechnical engineer, and the footing itself may be designed structurally by a structural engineer. The primary design concerns are settlement and bearing capacity. When considering settlement, total settlement and differential settlement is normally considered. Differential settlement is when one part of a foundation settles more than another part. This can cause problems to the structure which the foundation is supporting. Expansive clay soils can also cause problems.
Mitchell – Foster – Young House
Rotting at the corners where vines and moisture encroached finally undermined the integrity of the structure and the unoccupied house was in danger of collapsing in 2005, when a plan to repair it was created. Those plans were abandoned when termite and other animal-caused damage was discovered. The house had been originally built too close to the ground, making it impossible to avoid future similar damage if the house was simply repaired without a proper higher foundation. Alternatively, a plan was implemented to completely restore the house by dismantling it nail-by-nail and board-by-board. A newly built barn housed the methodically marked and cataloged timbers and boards, until a new, raised foundation was built. Then, in reverse order, the timbers and boards were reinstalled.