Close the gap between the neighbor's house and our house

Hello,

does anyone have a tip on how we can solve this.
During our house construction in the existing development area, gaps have formed between our houses on one side towards the neighbor, which is why the bricks could not be plastered due to the narrow space. See photo, there is also a gap on the front side, but it runs towards the back and closes like a triangle. I want to close both soon to protect the unplastered bricks from moisture. Due to the narrow space in the gaps, my idea would be to cut Styrodur to size (it is easy to cut to size) and glue it in with a slope towards the front, above the point where there is still plaster on our wall. (However I get in there). If larger gaps occur on the right or left, reduce them with a joint filler profile and then seal with all-weather sealant from the syringe. Then paint the whole thing white so it is not so noticeable. Would that be an option? Can we do it like that?
Thank you

would be my idea

…in my eyes a bad idea.

I want to close both soon to protect the unplastered bricks from moisture.

If you want to protect something in between, I would do it from above – roof extension and that’s it. Insulating from the front and back I consider the wrong choice and pointless.

We wanted to glue Styrodur above the top of the unplastered bricks to protect the gap and the unplastered bricks from rain.

If you want to protect something in between, I would do it from above - roof extension and that's it.
I consider insulation from the front and back to be the wrong choice and pointless.

Roof extension? That would then be the neighbor's house. Would the neighbor have to change something on their roof so that our unplastered wall is protected from rain?
Or is it meant differently?

That would be the neighboring house.

Why? Don't you have a roof on your building? Where exactly is the border?

Why? Don’t you have a roof on your building? Where exactly is the boundary line?

Of course we do. However, our house is 5-6 m higher. The course of the properties is ascending. The boundary runs directly between our houses. The roof extends up to the boundary. Even if we were to extend our roof, due to the difference in height, the wind would blow the rain into the gap. So only the neighbor’s roof would remain.

Are there no possibilities to insert something between our facades? That drains the rainwater to the front and prevents rain from entering the gap. Is cutting Styrodur to size no option? It doesn’t absorb any water and with a slope out of the gap, it should drain quickly anyway.

Boundary construction 6m high? That was not immediately apparent.

Unfortunately, I am not a technical expert. From experience, I would say that you always need a roof that collects and directs the water away. Clamping and sealing something in between does not solve the problem in my opinion, if water falls on it from above and the thing cannot dry again. But maybe someone else has an idea.