I've been asked to approximate a dollar amount for heating and cooling an occupied tenant space in a commercial office building. We've looked into installing a temporary gauge on each unit to give us a good approximation, but the cost to gauge up all the electrical and gas was beyond the scope of what I'm allowed. I even looked at just gauging up a few and approximating the rest, but that wasn't feasible either. The only variables I can provide are square footage, head count, and a possible computer count. Any ideas on how I can come up with a reasonable number? Any help is appreciated. Mac Additional Info - This space is controlled by 8 package rooftop Lennox units, varying between 3 and 7 tons.