If you tap the service conductors ahead of the main, these are still service conductors, and are subject to all the rules of services. You cannot run service conductors through building #1 to feed building #2. (230.3) Either make your connection outside the building (10x10x4 J-box) or feed through a CB, as discussed.
[This message has been edited by earlydean (edited 12-07-2005).]