Here's my first real attempt at interrior work. Believe it or not, there is NO ADDITIONAL LIGHTING in this shot; not even a reflector. The room has large windows that face north and are covered by a blind to hide the ugly stuff outside.

This guy shoots all of his interiors with all ambient light. No supplimental lighting. http://www.interiorphotography.net/

Nicely done! The majority of my commercial interiors are shot with available light using graduated filters to balance luminance values. Once in a while I encounter a commercial interior that requires extensive lighting, and that's always a huge undertaking.

I'm not a big fan of shooting residential interiors with available light unless requested. There are a few magazines that insist on available light shooting, however I've found that most residential interiors are improved with some well placed lighting.

Best,
Alan