How does LEED view buildings designed per UFC?

Can anyone advise how I should go about running the energy model for a building whose supply air & outside air quantities are being driven not by actual load, but by Unified facilities Criteria (UFC)? Should my proposed building airflow & subsequent energy use be reflective of the minimum REQUIRED airflows per ASHRAE and our proposed building envelope... or by the minimum ACH rates dictated by UFC? How do I compare "apples to apples" with the baseline rotations that are governed by ASHRAE? Thank you for any help that can be given... there is a DRASTIC difference in energy usage with these two methods.