What a wanker,not consulting you first.I have a similar problem where I live but it's more my fault really as some wood fell down in the heavy winds and broke some of their fence (your fence incedently is the left hand side as you see it from the street).the fence is literally a few shitty posts with bits of half cut logs on them,a good 50p's worth!!Below that is a wall that's completley fucked,only a brick high which they've now decided to dismantle and put all the bricks on my side,although it has fuck all to do with me and they said the other day that they'd put the bricks on my side for when I rebuild the wall!!!!fuck off,I screwed a few bits of feather edge into the posts and left it at that,I showed them that the whole wall is shagged and no more was said.really,it depends upon your relationship with the guy as to what to do about the fence/trees etc. I don't think you can do anything legally about it but you could say your not happy and offer to go halfway on the cost of putting a new fence up otherwise your paying for it yourself if it bugs you.I think I'm going to have to fund it out of my pocket in my house as I don't like the lack of security of people getting in through theirs,it's mega low crime where I am but still.I think 6'6" is as high as you can go on a fence,plenty really.