I am not sure what buildings are smoking at CBR. Why not try looking through the CBR FAQ thread listed below. That is a great source of information on CBR.
If you have any other questions on CBR please post there and you should get lots of responses.
I have not been to CBR yet but asked this question awhile back. I was told the smoking buildings were Trinidad North 31, Martinique 21 and Aruba 51. Hope someone else can confirm this for you! Have a great trip!