I was recently DP for a commercial shoot here in the UK, in a studio, and the director wanted it to look as real as possible. So I simply placed all the light sources where they would naturally be in a real house.
See photo below: The two windows in the photo have 1.2kw HMI PAR through 1/4 diff attached to the window. To the left is a 2.5kw HMI through a large silk (this was my large 'window', and the key). Behind the camera is a 12x12ft bounce with 1.2kw HMI PAR - this was important as there was no wall here and so there would have been a large black hole. We had a stretched textile on part of the ceiling too to give natural bounce. Another 1.2kw HMI PAR was used with Hollywood Frost through the french doors for a slightly soft sunlight (we only get soft sunlight in England!).
http://www.yorkshirecameraman.co.uk/121A5783.jpg