I am working on a project where two buildings directly adjacent to each other but separated by 10-20 feet are being designed to be connected by an underground tunnel. At the surface these buildings will also be connected by a stairway between them. We would like to be able to certify these two structures together as one building- does that seem like a reasonable approach? The other twist is that the buildings may be built in phases- one building one summer and the second building the second summer. I assume if we can treat the buildings and certify them as one this would only affect the timing of the construction phase submittals (that is, we would have to wait for the second building to be completed to submit). Does this sound on track? Feedback is much appreciated.