Bricks, Masonry, Asphalt and Concrete - BIG Wall crack - Please help - advice

I am looking to buy a house and think I have found the perfect one for me, however, the 1930's house has a ground floor kitchen at the back (single floor nothing above it), it has also had an extension put on the end (during 1950's). The (original) kitchen wall has 2 smallish windows and a door in it, the wall has also been pebeldashed. about halfway between the door and one of the windows there is an enormous crack (at about 20 degree angle) which reaches from the floor to the roof and has its widest part (about 1/2 inch) at its centre. It is difficult to see if the crack is only in the pebbledashing or if it is right through the wall. The inside of the wall is wood covered so i cant tell if the crack is on the inside too.

Apparently a tree was removed from the garden at some point in the past however I do not know if this is related in anyway

I realise there is a chance this could be subsidence (something which really puts me off purchasing the house) however the crack is not too close to a window or door (aparrently a sign of subsidence)

I am therefore not sure whether to risk paying out for an expensive survey when there is a good chance I know what the outcome will be.

therefore what i would like advice on is what else this could possibly be? and does it sound like subsidence to you?

I really do not know what to do and am desperate for any sort of advice, thanks in advance