Mount privacy screen on a sunken, slanted wall

The foundation is what is in the ground; you should look at the depth. How big is the height difference between the neighbor's terrain and yours? - who is higher? The little wall is probably tilted due to the load from the cars, which I deduce from the tire tracks; maybe the situation is also somewhat undercut?

That's what I meant with my statement, that's why I can only say tonight how deep the foundation is, because for that I have to lift a few stones and dig a hole.

Can't you agree with the neighbor that he lets his cherry laurel grow higher and you cut it back from your side in return? That would be the simplest - and prettiest - option.

I guess it would take 3-5 years to reach the desired height; it's probably been there for quite a while and is well-rooted.

That would also be a solution that would be okay for the neighbor (I had also discussed it with her once), but my partner would prefer to have privacy sooner rather than later. However, if the wall is not an option at all, she might have to reconsider this idea.

How large is the height difference between the neighbor's property and you? - who is higher? The little wall is probably tilted due to the load from the cars, which I conclude from the tire tracks; maybe the structure is also somewhat undermined?

completely forgot: we are a bit higher but not much. About 15 cm. The previous owner regularly used the garage to park her car, so it is quite possible that the wall sank due to the weight of the car. However, we only use the garage for bicycles now, which wouldn't even be possible with a car because of the garden gate. Therefore, no major load is expected there in the future.

So I only got around to digging today. The wall is about 67 cm high from the top edge to the "bottom edge" of the foundation. Since on our side, at the height of the garage where we want to install the privacy screen, it protrudes about 10 cm out of the ground, it is therefore about 57 cm in the soil on our side; on the neighbor's side, which is a bit lower, it is about 42 cm.

So not as deep as a foundation should actually be set, to my knowledge. Is it possible to calculate with these data how much lateral pressure a privacy screen can exert before it overturns the wall? Or does anyone here have experience or further ideas?

You don’t have to build a 2-meter-tall, heavy monster there, do you? It could also be suitable reinforcing steel mats that are planted. If simplicity is also a goal, it might be an option for you to anchor a timber beam on the outside of the garage wall and then make 2-3 panels from there. How about removing a few bricks every 1.5-2 meters and, for safety, going directly into the concrete underneath, e.g. with a simple metal foot from the hardware store? You then put the post in there and move on to the next one. You can keep the panels in between fairly light, i.e. wind-permeable, so why should they fall over? It would be different if you were putting a glass patio roof on top, but a simple privacy screen should hold up, or am I missing something? To prevent the bricks from breaking off from the concrete, I would remove them in that area. Afterwards, you can rebuild it attractively.

hmm... I personally don't like the reinforcing steel mat that much. I definitely wanted to have wood there. The privacy screen I had planned so far to recreate is the one Jonas Winkler built on Youtube (Google Jonas Winkler Zaun), maybe that as information so it's clear what we want to put there. It is definitely also air-permeable.

Regarding bricks breaking out, I haven't worried about that at all yet, my concern was more that the wall might completely topple over with the privacy screen on top (or at least lean further to the side, causing the privacy screen to stand crooked). But that's a good hint, it should be easy to solve by drilling four holes through the clinker per post all the way down into the foundation, then inserting correspondingly long threaded rods and fixing them with injection mortar, and then screwing the U-post holder onto the wall (with washers for alignment)?

Maybe I'm overthinking it, I saw today that on the other side of the property my neighbor installed a standard privacy screen (so 1.80m high) with simple drive-in sleeves in the ground (so without concrete, although it’s also more sheltered from the wind there). So, if your only concerns are that bricks might break out, that definitely helps me a lot, especially if it can be solved with longer threaded rods.

hmm...I personally don't like the construction steel mesh that much.

....when it's overgrown it's gone.....

my fear was more that the wall would topple completely with the privacy screen on top

exactly why I would remove the brick where a post is going, so that the metal profile rests directly on the concrete. Then you can just reinsert the little stones, why drill through there. If they break off (they probably will break when drilling anyway) your fence will be standing on toothpicks.... that seems unnecessarily complicated to me. Just glue the stones back later and that's it or remove the stones completely and replace with something else according to taste.