This is his wall or rather these are his bricks but on your side.
It is well settled law that anything which is attached to the land becomes part of the land so the wall which is now built on your side, you are quite entitled to claim.
BUT if you don’t claim it, then after 10 years he can claim adverse possession of that piece of land and the other side of the wall closest to you becomes the new boundary.
Although this might seem a very minor problem it’s actually a very complicated legal argument if it comes down to it.
In essence, you can say that it was very kind of him to build that wall on your land and to give it to you.
So can he either agree to what you want or get his bricks off your land please?
This is on the strict understanding that it’s not been there for 10 years because after 10 years if he use this wall exclusively the could claim adverse possession but in the circumstances he hasn’t because you have put stuff on top of it.
He would therefore need to have waited 20 years to have an easement for the wall to remain in place.
Thank you for letting me assist you with your legal question. I am glad that I was able to help.
I am not certain whether that answers the question for you or not, but I am happy to answer any specific points arising from this.
It will be my pleasure to help you again either further with this or any future questions you have