Unrenovated gross square footage

It depends on how you've drawn your LEED Project Boundary and what you are attempting to actually certify:

1) If you are attempting to certify just the addition (and it meets all of the MPR 2 addition requirements), then your LEED Project Boundary should not include the existing, unrenovated building. That existing building area should generally not be included in PIf2 or the rest of the application (there are a few site/share amenity exceptions). In this case, you are just certifying the addition, not the whole structure.

2) If you've drawn your LEED Project Boundary to include the existing, unrenovated building, then you are really claiming that the entire building will be certified in that application (both existing + addition). In this case, you would need to include the unrenovated area in PIf2. Additionally, you would need to update your application to make sure that all of the unrenovated space is included in the credit documentation as applicable. In this case, you are just certifying the whole structure (existing building + addition).

Form your inquiry it sounds to me like your LEED Project Boundary may be drawn incorrectly at the moment (as it appears you wish to certify just the addition based on what you've noted was included elsewhere in your application)...