This question isn't eQuest specific, but deals with 90.1 interpretation.

For an existing building, with regards to shell alterations, G3.1.5-f says
that "the baseline building shall reflect existing conditions prior to any
revisions that are part of the scope of work being evaluated." Is this
statement as far-reaching as I believe, indicating that U-values, SHGC etc,
listed in Tables 5.5 and Appendix A are ignored in a similar way as done in
the proposed, since the "baseline" in this case is a real design, rather
than a hypothetical baseline?

Kent Beason