Some meshes not displaying texture when others are

I have imported a model of a house into unity, all seems to be going well, until i try to apply a shader to parts of the house. If I apply my roof shader to the ground plane (which is in the house model) it works fine, however, when I apply the same roof shader to the roof of my house It only shows up as a simple colour of the roof, and isnt displaying the texture.

This kind of thing seems to be happening all though my house, where some meshes display a texture and others do not.

I dont believe this to be a shader problem, as the shader works on some parts. but I cannot work out what could be wrong with the other meshes. I’ve checked my UVing and everything seems fine.

Thoughts?

Do textures work with Diffuse shader? Can you post you “roof” shader?