Ha I was in exactly this dilemma.The way I would deal with this is to do a bit of reverse psychology make your neighbour feel its more for them than you. Build a wall/screen next to the wall ,screen would have less impact and quicker, higher than the existing wall explain before hand your decking is impacting on "their" privacy. It worked for me .Good luck

Thank you but the problem with building something else against their wall is that I have decking already in place and therefore have nothing to attach screens to as I cannot affix on to the side of the wall in my garden - I would have to take out at least one plank of my decking to fix something in. I was considering planters along my decking and putting in grasses or bamboo which is still an option but I fear then they will be difficult to move when maintaining the decking.

I'd buy wedge grips or bolt down 75 mm post supports, affix them to the deck, insert fence posts, string a fence you like the look of between them. Personally, I'd take the top of the fence above those seventies bricks, so the whole view is blocked - so long as you don't exceed 6 foot from the ground, you're perfectly entitled to do that without anyone's acceptance or permission. Maybe choose a fence panel that has an integral trellis on the top, if you want a more open feeling. You may want to paint the wedge grips afterwards - they're usually a maroon colour.

You could use pots with bamboo - but they'd be heavy to move once in large enough pots and won't completely block the bottom part of the wall which is visible now. I also wonder what condition they'd be in after your neighbour next decides to paint the wall...

That is a excellent idea by Bamboo,use post supports screwed bolted to the decking.You could also make your screen lightweightish example like a trellis frame,cane screen like suggested 6 foot ,with a little planning maybe make em removable.Its hard to gauge your neighbour but the suggestion of tall plants in pots taller than the fence maybe in flower would please most people and get them "onside"a bit.Something that gives impact all summer in blooms and keeps its foiliage all year round

If there is an evergreen that blooms all summer I think there will be a ot of people easgerly wanting to know what it is?

By impact Steragram I meant something pleasing to look at good for all summer whether attractive foliage,maybe flowering or not(others will have better ideas than me) and preferably evergreen for all year interest,in the pots against the screening would detract from the screening and hopefully keep your neighbour on side.Its better to not be seeming confrontational with your neighbour if possible.

Sounds good Cheqa - but its surprising how many questions appear on Goy asking for evergreens that flower all summer...