How to define the "project's energy-related systems"?

I am seeking clarity on this point given the GCBI's June 2011 update of MPRs and the current emphasis on defining a project "in it's entirety". Understanding the requirement to commission every energy-related system that serves the tenant's space starting from the point of origin for that tenant space is relatively straightforward in theory; it's the practice that has me nervous. Unless a wholely independant system, or sub-systems are used, how far *back* will one have to go (i.e. what of base building system heat pumps and Air Handlers with individual VAV boxes in the tenant space): do the HPs and AHUs that ultimatey serve the tenant space have to be commissioned? This is a relatively small tenant in a very large development, and the cost of commissioning could make this an impossible venture (sad, given that the tenant is a nonprofit that promotes and funds various sustainable enterprizes). As always, big thanks to LEEDuser for being there!