I may be misreading one of your emails, but if you are doing a building
renovation to an existing building, even if you ARE changing out
windows, the baseline model retains the envelope characteristics of the
existing building. You don't have to bring the baseline windows up to
90.1 standards unless it is a portion of the building that is being
added under the proposed work.

Also, check the archives - I thought that some GBCI reviews of projects
have required the four orientations even for existing buildings.

James Hansen, PE, LEED AP