Rose support

I see you don't want more trees, but I had an idea that columnar cypresses (or similar) could work well for excluding visibility of neighbours. Those are evergreen.

 

While you are still in the design stage, be mindful of the fact that although boundary fences may be restricted in height, 'temporary' structures such as pergolas, arches, etc face no such limitation. Your plot seems generous and would easily allow a construction or two to support many plants of differing characteristics. Consider also architectural plants, such as these:
The Plants - Architectural Plants
Website for both purchase and inspiration

 

Thank you but sorry @Alisa, conifers of any kind are taboo. I've had drain and foundation damage in the past from neighbouring conifers that cost thousands to put right.

 

Thank you for your input @infradig but I've said I don't want any more shrubs, with the exception of a rose. The intention is to have a flower bed.

The problem with my neighbours is something I have to shut out, so I'm now back to thinking I need to construct more and higher fencing before developing the bed fully. The fencing, to shut out extreme light pollution from their garden, as well as ongoing issues with 11 cats, five of which are theirs. I want to restrict the cat traffic over that fence, so height will help and I have other ideas in mind that I can use. I realise that cats can't be stopped but I can certainly hamper their movements.

 

Light pollution in gardens is within the scope of the UK Environment Protection Act 1990. The Local Authority are responsible ; they should be your first port of call.
Within the scope of this forum, advice regarding cats is restricted to that which is legal.

 

@Sheal Planting pyracantha up against your fence might deter cats - very thorny and it's evergreen, has spring blossom, autumn berries and year round interest for you as well as plenty to offer wildlife in terms of shelter and food.

Rusty trellis won't help with your light pollution but, if you use rusty metal uprights it can be much higher than standard wooden fence posts and you could grow a mix of rambling roses - some repeat flower - that can get large enough to cover it. Not my personal choice but a clematis armandii would be evergreen and provide early spring flowers unless you get nasty frosts. It's only hardy to -10C so the foliage won't do well in cold periods either.

Here is one of my rusty trellis panels in front or the old ruin wall


and here's the rusty chicken pen with clematis and honeysuckle to give shade

 

Thank you @infradig. I am well aware of the laws and regulations regarding garden issues. At the moment I'd rather deal with the problems, if possible, from my side of the fence. They are not bad people as such but don't seem to respect the people they live amongst. At the moment I'm also trying to deal with their constantly barking dog. I've had words about that but things haven't improved much. The local dog warden will be my next port of call if necessary and in this area they don't take any nonsense from owners.

I have no need to refer to the thread regarding cats. Again, I will deal with the cats my way within legal regulations.

 

Thank you too @Obelix-Vendée.

Pyracantha would give me the height I need and help with the cat situation. However, it's slow growing and I need to deal with the problem over the next few months if possible. The weather here at the moment isn't helping and by the end of November we usually see snow, so there will be little progress this side of the new year unfortunately.

Rusty trellis is a good idea but it's not ideal for what I want to achieve in the area. The more I think about this, the more I think it will mean another, higher fence inside the original. That, being solely my fence, I'll be able to attach what I like to it and still aim for a rose to brighten up the area.

I've got time to mull over all the suggestions given by your good selves here, as I still have the groundwork to sort before the fence is dealt with.