9128 tris, 4672 verts. Metal sheets and the cloth "door" are split into separate objects. Originally intended for a city building game. Not meant to be seen from the inside.
All textures has normal maps. There is no environment map or background images.
In hindsight, I should've scaled down the normal maps as well as used a lossy image format like JPG.
Thank you for the upload.
However, I have to wonder why the blend file is so friggin' huge (59MB). 4,000 + vertices is not large and there are no high-detail textures apparent in the preview image. Could it be that there is a very high res environment map or background image.