We have been noticing a number of cracks in our house we have been living in 3 years. Some are alongside the outside wall of a 1970s extension. 2 years ago we also made some remodeling of the inside (removed a load bearing wall) in this extension part. How do you know if they are subsidence or settling? And if they are subsidence what do you do? Call a surveyor? Or structural engineer? Then what kind of options are there. Could they say do nothing and just wait and see?