if you have a problem that when previewing materials, the building has the material and is displayed correctly, but in the render, the object is still dark


you can try to give the material a "subdivision surface" modifier. it is quite heavy, so trust that the blender and the computer will withstand it



after that, give him an easy way and you can safely remove the render to zero (also, to return, you can remove the level viewport to zero) do not set the render to 0! then the output will have black textures again!


if this does not work at all, try to apply a modifier, but first prepare the model and remove the black polygons manually, and apply materials to glass, etc., if you apply, you will simply highlight more complex polygons

also-sometimes, to correct the black bars, you can apply all the transformations and shift the center of gravity to the geometry

enjoy the rendering