I am in the process of simulating a 21 floor building, divided into three uses: offices, school, and retail space. None of the floors are planned and the offices have yet to be designed. If I simulate the proposed building with the baseline HVAC system (per ASHRAE 90.1 appendix G defined criteria) there will be little energy improvement. The only thing at our control is lighting. Has anyone been in this similar situation? any help will be greatly appreciated.