I've uploaded a video tutorial to explain how to achieve architectural glass. I have to mention that is not an official solution but a trick to obtain the effect without post prod.
The tip is from ttaberna in this post : viewtopic.php?f=9&t=4997&hilit=architectural+glass&start=0
You tube version in HD with annotations
Vimeo version in HD
[vimeo]http://www.vimeo.com/20676421[/vimeo]
All Videos are available on my Octane render playlist on Youtube http://www.youtube.com/my_playlists?p=740E81D11FA05AEB
And on Vimeo Octane render album http://www.vimeo.com/album/1546091/format:video