Advice on possible future fencing issues

Evening,
Thought I'd drop an inquiry to the brain trust here as to possible issues surrounding fencing around my back garden. It's not an issue at present and I'm just looking for advice or pointing to websites so I can get more info on where I stand and what both I or my neighbours may need to do in the future.

Background:
My parents bought the mid terrace property back in the early eighties and we enjoyed 20 years of good relationships with our neighbours on both sides. Time moved on and first one then the other sold up and they were converted / are used as BTLs with multiple people living there.

Facing the house in the rear garden the left hand boundary had always been a large full length hedge that both the neighbour and we used to trim. As far as I can tell the roots originate in his garden but it was used to mark the boundary. When neighbour #1 moved in they cut it all down and put up a 3 foot fence in it's place. This shocked my parents as it was all done in a day whilst they were at work. At the time we hadn't had any issues with the new neighbours and as they had replaced / maintained the boundary my parents didn't see the need to say anything. And in all honesty it the hedge belonged to my neighbour as I feel it does then it's his right to do with as he pleases.

Over the following years the people who rented there caused enough hassle that my parents decided to erect their own 6ft fence on their side of the boundary to enhance their privacy. We maintained the fence but in the later years it fell in to disarray and with the gales we've had these last few years the middle has fallen away and the rest is bent and bowed. It all needs to be replaced as it isn't really any good at all.

My mother passed away recently and through probate I am now the owner of the house and live there. I fully intend to replace the fence with another (haven't decided on height yet though will probably go with 6ft again.) The questions I have are where do I stand when I speak to my neighbour? He has let the hedges grow back but they aren't full length and so don't cover the whole or even a 3rd of the length of the boundary. This 3ft fence has also fallen apart and is just littering the ground underneath his hedges. They I feel also contributed to the demise of our old fence and I've had to cut back the hedge that over grows our fence and pushes it out twice a year.

I fully intend on paying to replace 'my' fence and don't expect anything from the neighbour in respect of costs. What I'm interested in is where we might stand on his hedge that will continue to grow, over hang any fence erected and press on the fence more and more. The neighbour hasn't trimmed or cut the top or our side of his hedge in many many years and I always return all cut trimmings to his garden after I'm forced to cut overhangs. The fence was put up by my late mother and I and we thought we had done a bang up job, looking back maybe we didn't do as well as we thought and if professionally erected and supported a new fence would withstand the pressures from the hedge and gales.

If I choose to replace the fence with another 6ft one I guess there isn't anything I can do about the hedge. Can I say buy an electric trimmer and once a year run it behind the fence to trim down the side facing our garden?

I don't plan on doing it this year as there is more important stuff around the house that needs addressing and I am still maintaining the boundary. I fully intend to try and find the landlord and speak to them to see if they even want the hedge or if as I'll pay for the fence they would mind me getting someone in to professionally remove the hedge so it doesn't grow back. Just after some advice before we actually meet up.
On the other side of the garden is another matter, in that for 20 years our old neighbours had a 3ft chicken wire fence that we were both fine with and had a really lovely relationship with the elder couple. Unfortunately as with the left hand side they sold up and the new owner let the wire fall into disrepair and left the boundary unmarked.

3-4 years ago he approached my mother whilst she was leaving the house one morning and said he was looking into getting a large fence put up and thought she should pay 50%. At the time he said he wanted a large sum (I can't remember exactly what it was but it made my eyebrows raise,) to which my Mum replied that he should come back to her with 3 written quotes and they could talk again.

2-3 weeks later she woke to find workmen in the garden erecting a 6ft fence the whole length of the garden and he never approached her again about it. Step forward a few years and I'm in the house most days dealing with the estate after she passed away and he approaches me as he's going in and I'm heading out, we exchange greetings. He doesn't realise or has forgotten my relationship to the previous owner and asks what "my plans are regarding the fence". I play coy and ask him "which fence" he's talking about and he says "the adjoining one". I state that I have "no plans for the fence as it's not my responsibility and that I am responsible for the other side of my garden and will in time be repairing that one". He replied that his deeds showed that I "was responsible for our adjoining boundary" (though my house's deed only delineates the boundary and doesn't assign responsibility.)

I replied that this was "different to my deeds" but I was "willing to talk about it more if he shows me what his deeds say". We had no further contact for about a year until this afternoon when we again bumped into each other outside the houses. He now says that he has "had another look at his deeds and they say that each house is responsible for the left hand side as you look at the house". I explained that this was "a general rule of thumb but that there was nothing on the deeds to state this". His understanding is the 'left hand side' relates to both the front and back gardens whilst facing the front of the house. Whilst I understand it as the left hand side when facing the front for the front garden and the left hand side when facing the rear for the rear garden. Or put another way, whilst facing the front of the house, it's the left of the front garden and the right of the rear garden.

As such he would in fact be responsible for the fence wholly if his deeds state this. He didn't look pleased but my lift to work arrived so we left it there to be picked up at a later date.

As an aside - his left hand side of his garden is fenced off and walled off as it joins on to a tile showroom who bought the garden from the next house over to extend they lot into. They have erected a very solid 8ft fence that has stood the test of time and doesn't need any maintenance at all. As such I feel he is trying to pull a fast one over a first time buyer and get me to pay for the fence so he doesn't have to.

That being said we would both benefit from the fence so I'm not overly averse to it, just feel miffed over the way he has gone about it so far. Also that as he has already erected the fence and wholly paid for it, it is his responsibility as he never spoke to my Mum about it beyond the initial request for payment.


EDIT = Neighbour has put up a fence 3 days after asking what my intentions were and that it was my responsibility.


Well that's it and probably all completely irrelevant and useless information but it's all there and thank you for hanging in there with me whilst I ramble on during a night shift. As I say, just looking to come from an informed and balanced place when I do eventually sit down with my neighbours individually to talk about the fences so any and all opinions, questions and ideas are more than welcome.