building energy performance problems.

[ZapBran]

I tend to use Vista to get charts of my energy use (one of the guys at IES told me that's what he does himself for UK Building Regs work too) and it shows me where the power is going pretty clearly for a first pass.
In the UK I've certainly seen the lighting energy coming in to play a lot (there's not always that much AC here because it's always so flipping cold) so maybe that might be a place where you could look at improving?
Have you introduced any dimming in your building or are the lights on 24/7?