I know what it is i make buildings to and i recommand learning blender wich is much better and easier when u understand how it works it took me a few days to understand it so its possible

See cslmodding.info, page "Building", section "UV Mapping" for what I mean.

I use SketchUp as described in my "real city" guide. I only use Blender for the conversion from obj to fbx and for a sanity check. But I don't think this is Blender specific. If you stick within your texture image in the first place (which btw. is impossible to check in SketchUp, but Blender shows it) then you don't have this issue. I do have it because I use it deliberately to repeat (tile) the roof image endlessly horizontally if the roof to be textured is large.

are you working with blender or ? because when I make an Lod it's just the the model without the extrusions

Not that easy: For the normal building I can (and do) use UV coordinates outside the 0-1 scope, for a repeating roof texture. This is not possible for the LOD. I would have to re-texture half of the building. (https://cslmodding.info/asset/building/#uv-mapping-lod)

just safe the asset before you gonna extrude the windows and name it _lod its really ez and it will make it more realistic of course its youre choice

I considered extruding the windows but it would greatly increase the number of triangles, making an LOD version necessary. This takes up lots of time which I would rather spend by creating additional buildings.

looks great maybe extrude the windows that would be awesome thanks a lot already ;)