Thank you gentlemen. This is a great help.
I recently discovered mapping uv's to different sections of a texture map, within a material. It works like a dream when you are updating dynamically from a .psd project. No creating new materials! I think, however, I have taken this past it's usefullness.
A tiling texture should be on it's own. A "details" texture map should contain 4 textures (eg) ... one for each side of a television. The difference is in ratio of the texture to the face. A brick is tiled to keep the scale close. A tv is already close. I will create materials mBoards, mShingles, mConcrete, mGrass and then create a details material mHouse (mailbox, window, door).
This approach seems to swim a little less upstream.
... and I was well on my way to having an entire video game rendered from one texture map.