Many properties are affected by structural movement, even more display cracking of some kind. Differentiating between the cosmetic and structurally significant is the job of surveyors and engineers and is a vital part of knowing what you will need to do (and spend) to keep your property in good shape.
Many ask what the difference is between settlement and subsidence, so here’s an offering of two definitions :
Settlement – this refers to the settling of a building’s foundations you could look here. Typically, it is the fact that different parts of the foundations move to different degrees that causes damage in the building’s structure.
This can happen for a number of reasons, though in private dwellings, failed drainage which washes away soil around parts of foundations is a very common cause.
Subsidence – this generally accepted as being the downward movement of the subsoil on which a building sits. Unlike settlement, this is unconnected to the weight of the building to force it down (ie the soil would have sunk even if there had been no property on it).
Subsidence can be caused by things such as mines, underground waterworks, consolidation of landfill etc.