I inherited a LEED project during the GBCI review period and I'm trying to make sense of our points for this credit. 

To meet Massachusetts stretch code, we modeled the baseline using ASHRAE 90.1-2013. We gained an additonal 3% savings through Interpretation ID#10481.

Since LEED v2009 requires a baseline that complies with ASHRAE 90.1-2007, could I also apply Interpretation ID#10421?

Would I use (% better than ASHRAE 90.1-2013 + Additional Percent Savings) to calculate my equivalent ASHRAE 90.1-2010 performance improvement and then use that number in the "ASHRAE 90.1-2010 Adjusted Point Scale for LEED v2009 Projects" document to determine points earned?

I'll need to reach out to a LEED coach for final word and how to document this properly, but I wanted to know if anyone has experience with this or if this sounds like a legitmate approach.