Chimney stack ownership and repair

[welshy21]

Tonyw We have looked in the loft and cannot see any part of a chimney breast on the side, I need to check insurance docs for the legal advice part but I know I can get legal advice from my union at work do you think this will be the best route to go down?

Alistair yes we are stepped terrace I think

 

[TonyW2]

Well if there is no structure on your premises and no fire needing a flue on that side it looks as if it must be his and without any chimney breast on your side I don't see how it can be on your roof
Free legal advice is worth checking if he will not cooperate and come to see your explanation.