is there a compliance path for multiple baselines?

I have not seen an interpolation table for LEED v2009 projects to apply 90.1-2013. You could try to make the case that 2013 is more stringent and therefore using it would produce a conservative result. You would then apply the 2010 adjusted point scale knowing you might be leaving some points behind. Creating a 2013 baseline and a 2010 baseline would not likely require huge changes so I don't see it as a major effort.

We also have a LEED v2009 project using ASHRAE 90.1-2013. Since an interpolation table does not yet exist for this do you have any advice on what should be done to gain additional points? Our first idea was since the adjusted point scale for LEED v2009 projects using ASHRAE 90.1-2010 gains 5 additional points (compared to using ASHRAE 90.1-2007), would it be fair to assume that there would also be a 5 point increase from ASHRAE 2010 to 2013?

The adjusted point scale for 2010 was based on the relative stringency difference between 2007 and 2010. The relative stringency between 2010 and 2013 was not as great so your extrapolation would not be correct. If it was my project I would just create a 2010 baseline model rather than try to justify some sort of adjustment in relative stringency of the difference in the two versions.

Thank you for your advice! We were considering making a 2013 baseline, applying the adjusted point scale from 2007 to 2010 and submitting additional comments explaining the situation. Do you have any sort of sources that analyze the relative stringency difference between 2007 and 2010 or 2010 and 2013? Or any sources on how the adjusted point scale from 2007 to 2010 was determined?

The US Department of Energy does a study on the relative stringency difference between different versions of 90.1. The study comes up with an overall average but that is misleading in my opinion. The study also comes up with the stringency difference by project type and climate. I would consider those to be more accurate. What they find is that the relative stringency varies significantly by these two variables. You could try to make a case based on the relative stringency difference between 2010 and 2013 but not sure it will be accepted. Submitting a LEED Interpretation is probably a better idea. Here is the study - https://www.energycodes.gov/sites/default/files/documents/901-2013_finalCommercialDeterminationQuantitativeAnalysis_TSD.pdf Regarding the adjusted point scale I am not certain exactly how that was determined. There really is no simple formula for these kinds of things.