I’m also a bit confused about your needs, anyway I was referring to what can make your scene to be a ‘complete’ scene, that is the ambient around the focused objects.
If you have metals or other reflective objects, as the most actually are, more or less, they will reflect the world around them; if around there’s nothing they will reflect black, apart from the specular lights coming from emitters.
The same is true for refractive materials such as glass or water, they will reflect or refract (let see through) what is around them.
As for the diffuse feature of materials, they will be enlighted by bouncing light from near surfaces, so a wall lit by the sun or other sources will cast a diffuse indirect light over near objects.
So if you want to make an internal view, the scene should be actually an internal, with walls and windows (holes on the wall or emitting mesh), a floor, etc. even if they are not seen by the camera.
As an alternative, you can use an hdr image as background texture, which will be mapped spherically all around the scene so to reproduce a full ambient.
I hope I’m clear enough
EDIT: I speak in general terms, I don’t know about BI and its materials, so maybe it’s possible to cheat somewhere, but in Cycles these concept are certainly valid.