Floor plan terraced house 2.5 floors pitched roof

I would be interested to know if a fixed glazing is possible in the fire protection wall to the neighbor.

I can’t imagine that. A window directly on the property boundary.

Neither does the window directly border the property line nor, especially, in a fire protection wall - no matter what the neighbors think about it. How about a roof window?

Neither windows directly on the boundary nor particularly in a fire protection wall are permitted – regardless of what the neighbors think.

Why not? If it’s only about fire protection, glass isn’t much worse than stones, or even wooden walls, right? What about glass blocks?

Neither does a window go directly on the boundary and certainly not in a fire protection wall - no matter what the neighbors think about it. how about a skylight?

That is not correct. Fixed glazed window elements are possible, which must have a certain fire resistance rating. Frosted glass is also probably possible with boundary construction.