Thanks for your reply numerobis...
The advantage (for me) of the two pass technique was that I couldn't duplicate the results I was looking for even by bumping up the interior lighting to an unreasonably high wattage (as you said), it didn't work. So really this was my shortcut to do it. The EV14 was to get the building exterior bright enough that I could tweak it in photoshop, and using the HDR image for illumination it isn't very bright anyway. If you set it low, you end up with an extremely dark building.
The multi-light you refer to doesn't exist in the plug-in for SU as far as I know. I love SU for it's quick ability to produce massing models, but for rendering I was looking for more. Given that the Maxwell plug-in was free it was easy to experiment and the upgrade to the production renderer was only $99, which was a lot less than the other solutions I was finding. Are there other biased solutions that would achieve an interior glow look?
It would be great to see how you or others have achieved an interior glow look for architectural renderings with a minimal cost outlay.
cheers...