@MartyW ,
Submetering is nothing new, but I have been out of the construction industry for nearly 10 years now, and just a recent transplant here, so I cannot suggest any local vendors. I can only say that best practice is to avoid using smaller companies that use proprietary rebranded hardware and software, and want to be your “turnkey” installation to billing service. It’s much better to have full control of your own. There’s a wild west of these who want to be your second utility company. Just Google “submetering” and you will see what I mean. As for equipment, there is a huge choice available from Eaton, Siemens, Leviton, ABB and others who offer “revenue quality” systems that are cost effective enough that ROI can often be achieved in a year or two. Here are just a couple: https://store.leviton.com/collections/sub-meters