I have a property in an estate built a few decades ago, there had been a fault line in the estate and some properties subsided. Then during the boom a builder wanted to build a large estate next door, kind of overlooking. He had obviously heard about the subsidence so sent a solicitors letter to everyone saying that they wanted to inspect and if they couldn't then any damage later caused could not be blamed on them (that was the gist of it). In my case I never responded, I ran it by my solicitor and decided to ignore them. That was a while ago, but I probably thought if they do damage then I'll go after them, no damage occured, but even if it had builder is long since evaporated. Hope this is of help to you Dewdrop.