Blender cookie architectural competition

Hello everybody,

I do not know if I ask it in the right place. But can you use textures from let’s say cg textures to give your scene all the textures you need. Or are you only allowed to use generated textures from within Blender. I have have never used outside textures. So should you use the external textures in a pinch or can you use as many in the scene as you like.

Good luck with the competition.