IES-VE vs DesignBuilder



Does anyone in the sustainability industry have comments on using IES-VE versus using Design Builder for Energy/Thermal comfort modelling.

I would like to find out practical experience comments on each software? Or any opinions on which is the better software to use?

Any comments will be appreciated.

Thank you.
Meghan Ward


Hi Meghan

I have only used Design Builder software, so my feedback comes from that perspective. Hopefully some others can share some thoughts on IES. In general though, see below.

  • I believe Designbuilder is more cost effective than IES
  • Designbuilder has good local support and training from GreenPlan (
  • I have however come across a couple of companies using IES locally for Green Star work. I know the WSP guys for example make use of it.


Hi Meghan

I agree with Francois regarding the benefits mentioned of DesignBuilder. In addition, DB is a user-interface to EnergyPlus which is arguably the most sophisticated simulation software tool available. EP is the accumulation of more than 20 years (even more - depends when you start counting) of experience by US department of energy. I believe DB has the strongest presence in SA. DB also offers many add-on modelling packages, which integrates with the normal energy simulation.
It is not easy to find energy modellers using both packages, although Francois Joubert (from Greenplan) did so in the past.
Here is a comparison done by Dru Crawly:

Finally, some more background on international energy modelling tools, from a recent poll.

I hope this helps answer your questions
Thomas Hugo


Hi Meghan,

In addition to the paper forwarded by Thomas, Dru Crawly (the author of the paper put together a nice online tool which “contrasts the capabilities of building simulation tools”.

It is a little technical but quite helpful.

Comparing simulation software has been an eternal question ever since there has been more than 1 software out there. At the end of the day, it’s all relative to the users’needs, the reason it is being used for, the simulation engine behind them, pricing and support.

Anyway, I hope that this helps a little bit.



Thank you Francois, Thomas and Yogesh, on answering my question.

The links and comments gives very good insights on contrasts. This info should also assist others when deciding what software to use.

Yogesh, I like this tool, it is useful. The IES-VE info doesn’t always come up though, but i’m sure they should update the tool. I will continue to refer to the tool.

Thank you.