This is the whintpartitionsecretdoor01.nif needed if you decide like me to make the entire 1st floor walls with the wood textures from the 2nd floor.
I changed the lightshader stone wall by the wooden walls to make the same matt texture. I enlarged the UV Texture to the same size as the wooden walls and repositioned the mesh texture in the texture frame to avoid overflow and get the same size board because the size of the mesh base of the stone wall make larger textures and therefore too big board .
Nif can be used by modder who decide to retexture the 1st floor walls with woods board (most of hjerim mods keep the ugly stones walls, the wood make the floor more warm), just add it to your mesh folder mod pack.