I'm working on a project that involves an expansion and a major renovation
of an existing building. My question relates to LEED modeling of the
existing building under LEED-NC.

The issue is that the existing building is significantly over-ventilated.
My team is involved in an energy retrofit of the existing structure and
intends to bring the OA rate down significantly. However because of the
equal vent rate requirement in Appendix-G, it seems like this won't lead to
any energy credit. As I understand it, no matter what we drop the vent rate
to (or even if we raised it), the proposed building will have to match and
the ventilation improvement will go unrecognized.

In case that's not clear, say the current building has 10,000 cfm of OA,
but we're going to drop that to 5,000 cfm with the new design. This leads
to significant heating and cooling savings. Can the baseline have 10,000
cfm because it's an existing building, or must it match under all
circumstances?

Thanks,

*Jason Kirchhoff*