Hello. We're trying to decide if pursuing energy modeling under Option 2's Path 1 would be worth the effort. The project is a tenant fit out of the 23rd and 24th floor in one of the two 24 floor attached buildings the central plant serves. The HVAC design adds a few terminal units and one split system to serve a server room in the project scope but no major changes are made to the central plant. I understand that the entire two building complex and the central plant would have to be modeled in both the Baseline and Proposed Cases. The local HVAC modifications' efficiencies are only slightly better than ASHRAE 90.1 prescriptive values. The design does not meet the Option 1 requirements.
Given this, is there a way to estimate if 15% HVAC energy cost improvement is demonstrable or not before the data collection and modeling effort is taken up? It seems like a tall order especially if only two floors of the 48 or so floors are undergoing modest improvements.
Thanks for your attention.