Seems like squatters rights. In the states, the length of time you need to reside and improve the lot depends on what state you're in. In Minnesota it's fifteen years. Plus you have to pay five consecutive years of taxes.
You do need to be able to *prove* that the house has stood for four years. Maybe take photos and post them to yourself, then keep the envelope unopened when it arrives, and hope the date stamp is visible. We made it to three and a half before the new neighbours decided we might be adversely effecting their potential profit margins and called the council.
It is not quite the same as squatters rights because they already own the land. They have won the right to live on that land.
I just find it amazing that the neighbours are now complaining about something that has been going on for over four years and has not effected them in anyway to such an extent that tey didn't even know they were living there.
Not very neighbourly
Burra Maluca, Do you have to prove that the house has been standing or that you have been actually living in it for four years.
Aman - it was in the UK. As I remember, to keep the building you had to prove it had been standing for four years. To get the right to live in it you had to prove it had been lived in for four years. But do some research and check current legistlation.