I have a problem here with textures. All the models you see are textured, except for the roof and floor. Those look grey, and when I textures them, they show only the main color of the texture instead of the detail in the textures. For example when I try to apply a red bricks texture, it takes the basic colour, red, but doesn't show the white color in the mortar lines between the bricks.
Here is how it appears in the world in Unity3D, after putting the texture:
Here is how it appears Blender