If you are asking this question, you are probably either really new to energy modeling or really experienced.
Unfortunately, nobody really has the answer to this flawed question. The problem is that best can mean a number of things. Some might think that it means, "The most powerful, flexible, modern software package". But if it takes 5 years to learn how to use it, would it still be the best?
Many would argue that EnergyPlus is the best energy modeling software package. I will say with certainty that, on it's own, EnergyPlus is not the best software package.
Why isn't EnergyPlus the best software package?
EnergyPlus is not a software package at all. It is an engine. It's like saying, "The Ford Ecoboost V6 is the best car in the world" (wait, EnergyPlus is U.S. government funded, so I suppose a GM engine would be a more appropriate analogy, but I use the Ford Ecoboost analogy because I sincerely don't want to insult EnergyPlus).
See, EnergyPlus is an awesome, powerful, flexible (albeit relatively hard to learn) engine. When combined into a package (Engine+Graphical User interface), it is on the list of top contenders.
So what is the best whole building energy modeling software package?
To discuss the best whole building energy modeling software, we should consider: ASHRAE Std 140 approval, power, flexibility, feature-rich, learning curve, existing audience, reports, customization, and maybe a few more things. You might care about cost too. The only free software on the list is eQUEST.
That narrows the discussion of best software down to a few software packages:
And the wildcards...
Hooray! That narrows it down from the several hundred that you might be inundated with if you do an internet search!
Now, for the proverbial spitting contest.
Please post screenshots from your preferred software that shows why it is awesome, and/or why it should make the list (consider an awesome graphic, or a really technical feature). Please post them in the comments below or email us screenshots at firstname.lastname@example.org
Energy-Models.com is a site for energy modelers, building simulators, architects, and engineers who want learn the basics, to advanced concepts of energy modeling. We've got online training courses and tutorials for eQUEST, Trane TRACE 700, OpenStudio, and LEED for energy modeling. All our energy modeling courses are video based. What better way to learn energy modeling software than screen-casts of exactly how things are done?