When placed by a window like SLgCWalWin01, which happens in a number of areas around the Bard's College, this mesh does not properly clip together, creating gaps. Editing SLgCWalWin01.nif does not work, as filling the gaps on its end creates zfighting, but Khrys was able to make a small modification to slgccolsol03 that improves how it connects to that window, filling the gaps, without affecting how it clips to other meshes. We spent a few hours testing every single placed instance of this mesh in the game and ensuring there was no clipping or zfighting anywhere.
It does make a tiny change to the object bounds so the esp adjusts for that.

Attached Files:
slgccolsol03.nif
slgccolsol03bounds.esp