Cracks right around room and now the floor

[lisach]

I am very worried about a potential issue with my parents house. Over time a crack has appeared in the ceiling, down the walls and now has started to crack the ceramic floor so in effect it joins up for the entire circumference of the the room. The ceiling crack looks to be where two joists are joining but now the walls and the floor have gone the same way I am worried. What on earth could cause a crack to go right around a room.

Many thanks

 

[BigRobCanUFixIt]

subsidence would be my guess. although Im not a pro and does it crack where an extension has been built. Pics might help a bit more.

 

[noseall]

What on earth could cause a crack to go right around a room.

 

[mixup]

subsidence would be my guess. although Im not a pro and does it crack where an extension has been built. Pics might help a bit more.

yes would it appear to be where the house had been extended?