Alison Wiles, 1st Associated Independent Chartered Surveyors says:  As part of our structural building surveys we often find cracking in the property.  The surveyor needs to establish whether they are long standing or progressive, then they are looking for the reasons behind them.  For example, problems with the soil Soil Information , trees Tree Information or the drainage system Drains Information 

Define terms, subsidence, heave and settlement.

You can have several types of cracks in your proeprty such as vertical cracks, horizontal cracks, diagonal cracks but we really need to see them to be certain what they relate to.  Lets give an example.  Horizontal cracks normally relate to wall tie failure (put sketch in).

If the crack is wider at the top than the bottom that is subsidence.