("Energy Simulation Tools" should probably be a Sub-Forum. I have compiled a pretty big list of other tools that Ecorenovators might want to try.)
I just came across a computer-based energy simulation tool called EnergyPlus that can be downloaded
free of charge at this URL:
Building Technologies Program: EnergyPlus Energy Simulation Software
It's the real thing, not a trial thingie.
There are also plug-ins and files, etc. that make this very promising.
So, it is possible to "build" a virtual house, insulate it as you wish, and see how it performs in any location that you specify... like where you live, for instance.
Your tax dollars at work.
Check it out.
-AC_Hacker