October 4, 2001
Looking at your questions I really do not think the true performance based design would really apply. The performance based code option could cover these items if the stakeholders felt these were issues that would need to have a performance based design.
The guidance for how these are accepted depend on what the stakeholders of the project are concerned about. For instance if the concern is to limit the amount of fire separation, then the stakeholders must be assured that there has been provisions put in place so the fire separation is not required.
Performance based codes are a great thing, which will require a lot of educaiton for code officials. Please remember that performance based codes will not realy work on water vapor in gas, it will typically work well in those large concepts that are not typically covered in the building codes
Hope this helps