It has been difficult to use hdr lighting with indoor scenes because the walls block much of the light being cast upon the scene. No matter! That's easy to get around. Select the walls in your scene and go into the materials lab. Disable "cast shadows" for the material by going to the triangle menu located to the left of the first component window: The walls will no longer block the light from entering the room. Apply an hdr and render. That's it! Here's a quick sample render to show you that it does indeed work. This room has no windows and yet the hdr still penetrates the walls:

Thanks for that tip!  That's exactly what I came in here to find, and lucky me, it's right at the top :D

Thank you! It answered a question I had been pondering if it was worth asking.

Thanks Max,
I'm just going to start using Bryce 6 tonight and I love reading all your posts cause you have so many cool tips.
Ang